Blender 3D: Noob to Pro/Procedural Eyeball in Cycles

Blender

Knowing before Making

Blender is a powerful and complex 3D modeling and rendering package. However, before you can make anything, you need to understand several concepts used in 3D modelling and related fields. Examples include:

• Understanding the process of 3D modeling and rendering
• Understanding how the axis and 3D coordinates work in Blender.
• Understanding orthographic and perspective views.
• Local coordinates, parent objects, and child objects.
• Blender's user interface and how to navigate it.
• Viewing a scene from different camera angles

Don't be scared by their long names; a lot of these are actually pretty intuitive and easy to grasp. Of course, since you're not doing any actual modelling in this unit, you might be tempted to skip ahead, and that's completely fine! Just know that understanding these concepts well will help you a lot in the long run, and proceeding through tutorials in order will build a strong foundation for you to build on. Prior knowledge also plays a huge part in this, so if you're coming from other 3D software, you should already be familiar with these concepts.

That said, the actual fun (making stuff in Blender) comes in the next unit. However, keep in mind that Blender is not the kind of software you can jump into and experiment with. It's notorious for having a steep learning curve. It's less like exploring an unfamiliar city and more like flying a spaceship; if you hop into the pilot's seat without knowing the fundamentals, it's going to be near impossible to get off the ground.

Blender-specific terminology

Like any subject, 3D graphics has its own words and terminology used to describe specific ideas. In this book, important words are highlighted and defined on their first use. If you've missed or forgotten the meaning of a word, try looking it up in the Glossary.

Things you'll need

In order to follow the tutorials, you need a computer with Blender installed. You can download the latest Blender release here.

Depending on your system, you may also need the appropriate Python installation. Each version of Blender requires a specific version of Python, but it's usually packaged with Blender.

The Blender team has the Blender Long Term Support program which provides a stable Blender version with 2 years of support. During the 2 year support window, no new features, UI changes, API changes or other enhancements will be done; only critical fixes will be applied. This allows teams working on long-lasting blender projects to use a single supported version over a 2 year period. Long term versions are indicated below with the LTS suffix and a year indicating the last year of support.

Blender version	Python version
2.79	3.5
2.83 LTS 2022	3.7
2.90	3.7
2.93 LTS 2023	3.9
3.0	3.9
3.1	3.10
3.3 LTS 2024	3.10
3.4	3.10
3.5	3.10
3.6 LTS 2025	3.10
4.0	3.10
4.1	3.11

You can check Python version on Scripting workspace using:

import sys
print(sys.version)

Installation instructions

Since Blender is open-source software, you can download the source code and build it yourself, but it's easier to download a pre-built binary. As of Blender 4.0, compiled releases are provided for the following operating systems:

• Windows 8.1, 10, and 11
• macOS 11.2 Intel or Apple Silicon
• Linux with glibc 2.28 or newer

Along with the website, many Linux distributions have Blender available in their package repositories, though it may be a slightly older version. You can use your system's package manager to download and install the package. It's also available on steam.

Windows users can also choose between an executable installer ("setup wizard") and a ZIP archive.

After the installation process is finished, Blender should appear in the Graphics section of your desktop environment application menu.

You may also want to download a 2D image editor, such as GIMP, Paint.NET, or Photoshop or a media player, such as VLC.

It's a good idea to have pencil and paper handy for sketching and taking notes. There's a lot to absorb. Taking notes as you go will pay dividends later.

Where to Go for Help

If you get stuck, you can ask for help from other Blender users in the appendices.

Additional Resources

Many modules have a section like this at the bottom, listing websites with information on the topics covered in the module.

• Blender system requirements

What Blender Can Do

In this module, you'll learn what Blender does, both in terms of the product (images) and the process (3D modeling).

Blender is a free software package for authoring "three-dimensional" (3D) graphics (also known as computer graphics or “CG”), including still images, games, and video.

While the end-product of most Blender projects is a two-dimensional (2D) raster image on a flat surface (be it a monitor, movie screen, or sheet of paper) except for Head Mounted Virtual Reality applications, the images are said to be "3D" because they exhibit the illusion of depth. In other words, someone looking at the image can easily tell which parts are meant to be closer and which are farther away.

An Example

Here's a realistic still image that was created with Blender.

"A Lonely House", by Mayqel

Look closely at the building.

• Because it is obscured by the building, you can tell that the tree-lined hillside is behind the building instead of vice versa.
• The way the top and bottom edges of the front wall appear to converge toward the base of the tree allow you to judge the angle between the front wall and your viewpoint.
• Your brain interprets dark portions of the wall as shadows, allowing you to estimate where the light is coming from, even though the sun is outside the frame of the image.

While an illusion of depth can be authored by hand with 2D graphics software (or a paintbrush!), Blender provides a much easier way.

It's likely that the lonely house never existed outside of the artist's mind. Instead of building a big set on a rural lot in Germany, waiting for the right light, and photographing it, the author built a scene in a virtual 3D world—one contained inside a computer. This is called CGI (Computer Generated Imagery). They then used Blender to render the scene (convert it into a 2D image). You can view more of what Blender can do at the Blender gallery: http://www.blender.org/features/

Steps in the 3D Production Process

To produce an image like the one above involves two major steps to start with:

• Modelling, which is the creation of your miniature 3D world, also known as a model or scene. This involves defining the geometry of the objects, making it look like they are made out of particular materials, setting up the lighting, and defining a camera viewpoint.
• Rendering, which is the actual generation of the image of the world from the viewpoint of the camera (taking a “photograph” of the scene, if you like), for your audience to enjoy.

3D is often used to produce not just single still images, but animations as well. This requires some additional steps:

• Rigging — setting up a rig, namely a way of deforming (changing the shape of) a character in various repeatable ways to convincingly mimic joint movements, facial expressions and other such actions of real-life people or animals.
• Posing — choreographing the positions of the objects and their parts in the 3D scene over time, using the previously-created animation rigs
• Rendering now involves creating a whole sequence of frames representing movement over time, rather than just a single still frame.

But that’s not all. There are frequently additional processes to embellish the results of the above, to make them look more realistic:

• Sculpting — a more organic form of modelling objects by shaping them as though they were made out of clay. This produces more complicated, irregular shapes which mimic real objects found in nature, as opposed to clean, simple, geometrical ones which mostly only exist in the world of mathematics.
• Texture painting — You’re probably familiar with programs that let you paint an image on a 2D digital canvas. Such programs are commonly used in 3D production, to create textures which are “wrapped” around the surfaces of 3D objects to give them a more interesting appearance. 3D programs also often allow direct painting on the surfaces of those objects, so the effect of the design can be observed immediately, instead of having to go through a separate paint-on-a-flat-surface-then-wrap sequence of steps.
• Physical modelling — simulating the behaviour of real-world objects subject to real-world forces, for example hard balls colliding, soft cloth draping itself over an obstacle under gravity, water flowing and pouring. Mathematical formulas are available for these that give results very close to real life, all you need is the computing power to calculate them.
• Motion capture, or mocap: producing convincing animations, particularly ones that look like the movements of real people (walking, running, dancing etc) can be hard. Hence the technique of capturing the motions of live actors, by filming them with special markers attached to strategic points on their bodies, and doing computer processing to track the movements of these markers and convert them to corresponding movements of an animation rig.
• Compositing — this is where 3D renders are merged together with real photographic/live-action footage, to make it look like a rendered model is in the middle of a real-world scene, or conversely a real live actor is in the middle of a rendered scene. If done with proper skill, in particular due care to matching the effects of lights and shadows, the viewer becomes unable to tell what is real and what is not!

And just to add another complication to the mix, there are two kinds of rendering:

• Real-time rendering is rendering that has to happen under tight time constraints, typically for interactive applications like video gaming. For example, most gamers expect the screen to be updated 60 times per second in order to render smooth motion and respond quickly enough to player actions. These time constraints impose major limitations on the kinds of rendering techniques that can be used.
• Non-real-time rendering is where the time constraints are not so tight, and quality is the overriding factor. For example, when producing a single still frame, it may not matter so much that it takes minutes or hours to do so, because the beauty and detail of the final image is worth it. When rendering a Hollywood-quality movie, it may still take hours per frame, but the use of a render farm of hundreds or thousands of machines, all working on different frames at the same time, allows the entire sequence to complete in just a few weeks.

But wait, there’s more: There are also some areas, which might be considered to be stepping outside of traditional 3D production work, where Blender provides functionality:

• Video editing — having rendered your animation sequences and shot your live-action footage, you will want to combine them in a properly-timed linear sequence to tell a coherent story.
• 3D printing — Many people are interested in creating physical objects using 3D printers. The shape data may be obtained from real objects with 3D scanning, or it may be created from scratch using 3D modelling, or you can even combine both processes.

Blender is a capable tool for every single one of these processes. There’s quite a lot there, isn’t there? But don’t be too intimidated: this Wikibook will take things step by step, and you will be able to produce some fun stuff from early on.

Additional Resources

• 3D rendering at Wikipedia.
• Render farm at Wikipedia.
• Comparison of 3D computer graphics software at Wikipedia.
• Computer-generated imagery at Wikipedia.
• Depth perception at Wikipedia.
• Blender Art Gallery
• Blender Homepage

3D Geometry

If you haven't previously studied 3D graphics, technical drawing, or analytic geometry, you are about to learn a new way of visualizing the world, an ability that's fundamental to working with Blender or any 3D modeling tool.

3D modeling is based on geometry, the branch of mathematics concerned with spatial relationships, specifically analytical geometry, which expresses these relationships in terms of algebraic formulas. If you have studied geometry, some of the terminology will be familiar.

Coordinates And Coordinate Systems

Look around the room you’re in. The odds are it will have a cuboidal shape, with four vertical walls at right angles to each other, a flat, horizontal floor, and a flat, horizontal ceiling.

Now imagine there’s a fly buzzing around the room. The fly is moving in three-dimensional space. In mathematical terms, that means its position within the room at any given moment, can be expressed in terms of a unique combination of three numbers.

There are an infinite number of ways —coordinate systems— in which we could come up with a convention for defining and measuring these numbers, i.e. the coordinates. Each convention will yield different values even if the fly is in the same position. Coordinates only make sense with reference to a specific coordinate system! To narrow down the possibilities (in a purely arbitrary fashion), let us label the walls of the room with the points of the compass: in a clockwise direction, North, East, South and West. (If you know which way really is north, feel free to use that to label the walls of your room. Otherwise, choose any wall you like as north.)

Consider the point at floor level in the south-west corner of the room. We will call this (arbitrary) point the origin of our coordinate system, and the three numbers at this point will be $(0,0,0)$. The first of the three numbers will be the distance (in some suitable units, let’s say metres) eastwards from the west wall, the second number will be the distance north from the south wall, and the third number will be the height above the floor.

Each of these directions is called an axis (plural: axes), and they are conventionally labelled X, Y and Z, in that order. With a little bit of thought, you should be able to convince yourself that every point within the space of your room corresponds to exactly one set of $(x,y,z)$ values, and that every possible combination of $(x,y,z)$ values, with $0\leq x\leq W$, $0\leq y\leq L$ and $0\leq z\leq H$ (where $W$ is the east-west dimension of your room, $L$ is its north-south dimension, and $H$ is the height between ceiling and floor) corresponds to a point in the room.

The following diagram illustrates how the coordinates are built up, using the same colour codes that Blender uses to label its axes: red for X, green for Y and blue for Z (an easy way to remember this if you're familiar with RGB is the order -- Red X, Green Y, Blue Z). In the second picture, the x value defines a plane parallel to the west wall of the room. In the third picture, the y value defines a plane parallel to the south wall, and in the fourth picture, the z value defines a plane parallel to the floor. Put the planes together in the fifth picture, and they intersect at a unique point.

Another simple way to understand what the coordinates of a point say (x,y,z) means is, if one starts from origin and moves x, y, and z units of distance parallel to x, y, and z axes respectively, in any sequence, one will reach that point. Thus, for example, a coordinate of (3,4,5) means the point which is reached when one moves, starting from origin, 3 units of distance along x-axis, 4 units of distance along y-axis and 5 units of distance along z-axis.

This style of coordinate system, with the numbers corresponding to distances along perpendicular axes, is called Cartesian coordinates, named after René Descartes, the 17th-century mathematician who first introduced the concept. Legend has it that he came up with the idea after watching a fly buzzing around his bedroom!

There are other ways to define coordinate systems, for example by substituting direction angles in place of one or two of the distance measurements. These can be useful in certain situations, but usually all coordinate systems in Blender are Cartesian. However, in Blender, switching between these coordinate systems is simple and easy to do.

Negative Coordinates

Can coordinate values be negative? Depending on the situation, yes. Here we are only considering points within our room. But suppose instead of placing our origin in the bottom southwest corner, we put it in the middle of the room, halfway between the floor and ceiling. (After all, it is an arbitrary point, we can place it wherever we like, as long as we agree on its location.) If the X-coordinate is the distance east from the origin, how do we define a point west of the origin? We simply give it a negative X-coordinate. Similarly, points north of the origin have a positive Y-coordinate, those south of it, have negative Y-coordinates. Points above the origin have a positive Z-coordinate, those below it, a negative Z-coordinate.

Handedness Of Coordinate Systems

It is conventional for most Cartesian coordinate systems to be right-handed. To understand this, hold the thumb, index finger and middle finger of your right hand perpendicular to each other:

Figure 1: The three axes form a right-handed system

Now orient your hand so your thumb points along the X-axis in the positive direction (direction of increasing coordinate numbers), your index finger along the positive Y-axis, and your middle finger along the positive Z-axis. Another way of looking at it is, if you placed your eye at the origin, and you could see the three arrows pointing in the directions of positive X, positive Y and positive Z as in Figure 1, the order X, Y, Z would go counter clockwise.

Figure 2: Another view of right-handed system

Another way to visualize this is to make a fist with your right hand, with your curled fingers towards you. Stick out your thumb directly to the right (X). Now aim your pointer finger straight up (Y). Finally, make your middle finger point toward yourself (Z). This is the view from directly above the origin.

Axes Of Rotation

Consider a spinning sphere. Every point on it is moving, except the ones along the axis. These form a motionless line around which the rest of the sphere spins. This line is called the axis of rotation.

More precisely, the axis of rotation is a point or a line connecting points that do not change position while that object rotates, drawn when the observer assumes he/she does not change position relative to that object over time.

Conventionally, the direction of the axis of rotation is such that if you look in that direction, the rotation appears clockwise, as illustrated below, where the yellow arrow shows the rotational movement, while the purple one shows the rotation axis:

To remember this convention, hold your right hand in a thumbs-up gesture:

If the rotation follows the direction of your curled fingers, then the direction of the axis of rotation is considered to be the same as the direction which the thumb is pointing in.

This gesture is a different form of the right-hand rule and is sometimes called the right-hand grip rule, the corkscrew-rule or the right-hand thumb rule. From now on we will refer to it as 'the right-hand grip rule'.

When describing the direction of a rotating object, do not say that it rotates left-to-right/clockwise, or right-to-left/counterclockwise. Each of these on their own are meaningless, because they're relative to the observer. Instead of saying this, find the direction of the axis of rotation and draw an arrow to represent it. Those who know the right-hand grip rule will be able to figure out what the direction of rotation of the object is, by using the rule when interpreting your drawing.

Additional Resources

• the Geometry wikibook
• Analytic geometry at Wikipedia.
• Cartesian coordinate system at Wikipedia.
• Right-hand rule at Wikipedia.
• Rotation at Wikipedia.

Coordinate Transformations

Coordinate Transformations

A transformation is any operation that changes coordinate values in some way. For example, if you pick up an object and move it to a different place in the room without changing its orientation, then the coordinates of each point on the object relative to the room are adjusted by an amount that depends on the distance and direction between the old and new positions. This is called a translation transformation.

Object at original location

Object translated to new position

Simply turning the object without moving it from its original location is called rotation.

Object rotated 45°

If the object were to get bigger or smaller, that is a scaling transformation. In the real world, only a few objects can be scaled in this way. For example, a balloon can be inflated or deflated to a larger or smaller size, but a bowling ball cannot. Regardless of what can and can't be re-sized in the real world, any object can be scaled (re-sized) in the world of computer graphics. Scaling may be uniform, i.e. apply equally in all dimensions, or non-uniform.

Object uniformly scaled to 50% of original size

Object scaled vertically to 50% of original size

Linear Transformations

The main types of coordinate transformations we’re concerned with are called linear transformations. Lines that were straight before the transformation remain straight. i.e. they do not become curved. For example, the following diagram illustrates three linear transformations applied to the square in the center: Clockwise from the left, a shear or skew, a scale, and a rotation, plus one non-linear transformation that causes two sides of the box to become curved.

Multiple Transformations

It is possible to concatenate or compose a series of transformations. The resulting transformation can do many things in one operation — translation, rotation, scaling etc. However, the order of composition of the component transformations becomes important. In general, transformations are not commutative. For example, compare the result of moving our model some distance along the Y axis followed by rotating it about the X axis (If this doesn't make sense, consider that the axes are fixed, they aren't moving with the object. More on that later Global and local coordinates):

Translation followed by rotation

versus the result of doing the rotation first:

Rotation followed by translation

In some instances, the three forms of transformation may be applied on a single object concurrently. Such a feature exists in Blender and is normally implemented in creating animations. For example, you can decide to pick up the object (first transformation - translation), twist it (second transformation - rotation), and, in a 3D modeling environment, increase the size of the object (third transformation - scaling).

Inverse Transformations

Often there is a need to find the inverse of a transformation. That is, a transformation that has the opposite effect. For example, a rotation of +45° about the X axis is undone by a rotation of -45° around the same axis.

Inverses have many uses, one of which is to simplify the construction of certain kinds of transformations.

For example, it is easy to construct a rotation transformation about the X, Y or Z-axis of the coordinate system. But what about a rotation of Θ° around an arbitrary axis? This can be made out of the following parts:

• a translation that makes the rotation axis pass through the origin.
• rotations about the Y and/or Z axes, as appropriate, so the rotation axis lies along the X axis.
• a rotation of Θ° about the X axis.
• the inverse of the rotations that aligned the rotation axis with the X axis.
• the inverse of the translation that made the rotation axis pass through the origin.

Most of the transformations we deal with in 3D modelling have an inverse, but not all. See the next section for some that don’t.

Projections

Most of our display and output devices are not three-dimensional. Thus, three-dimensional images need to be projected onto a two-dimensional surface (like a display screen or a printed page) before we can see them.

There are two main ways to perform such projections. One is orthographic projection, where parallel lines are drawn from all points of the three-dimensional object until they intersect a plane representing the display surface:

The other method is perspective projection, where the lines drawn are not parallel, but intersect at a point representing the location of the eye of the viewer:

Projections are also linear transformations. But since they take a three-dimensional space and flatten it onto a two-dimensional surface, some information is lost. Those transformations are irreversible i.e. they cannot be undone, at least in a unique way as the depth information is gone.

You will read more about both orthographic and perspective views in the following pages.

The mathematics of perspective were first worked out in the 11th century by Alhazen, and used to great effect by the Italian Renaissance painters four hundred years later.

Orthographic Views

Orthographic Views

An orthographic view (or projection) of a 3D scene is a 2D picture of it in which parallel lines appear parallel, and all edges perpendicular to the view direction appear in proportion, at exactly the same scale.

Orthographic views are usually aligned with the scene's primary axes. Edges parallel to the view axis disappear. Those parallel to the other primary axes appear horizontal or vertical. The commonly used orthographic views are front, side, and top views, though back and bottom views are possible.

Uniform scale makes an orthographic view very useful when constructing 3D objects, not only in computer graphics, but also in manufacturing and architecture.

Here's one way to think about the orthographic view:

Imagine photographing a small 3D object through a telescope from a very great distance. There would be no foreshortening. All features would be at the same scale, regardless of whether they were on the near side of the object or its far side. Given two (or preferably three) such views, along different axes, you could get an accurate idea of the shape of the object, useful for "getting the feel" of objects in a virtual 3D world where you're unable to touch or handle anything!

Example

Here is a drawing of a staircase:

An isometric view of a staircase

and here are three orthographic views of the same staircase, each outlined in red:

Figure 1: "First Angle" Orthographic views of a staircase

The views are from the front, top, and left. Dashed lines represent edges that, in real life, would be hidden behind something, such as the left wall of the staircase. (Think of each view as an X-ray image.)

The leading edges of the steps are visible in both the front and top views. Note that they appear parallel and of equal length in 2D, just as they are in 3D reality.

Additional Resources

• Orthographic projection at Wikipedia.

Perspective Views

As you know, the main reason for modeling 3D objects in Blender is to render images that exhibit the illusion of depth.

Orthographic views are great for building a house, but seriously flawed when it comes to creating realistic images of the house for use in a sales brochure. While a builder wants blueprints that are clear and accurate, a seller wants imagery that's aesthetically pleasing, with the illusion of depth. Blender makes it easy to use tricks like perspective, surface hiding, shading, and animation to achieve this illusion.

How does perspective work?

The essence of perspective is to represent parallel edges (in a 3D scene) by edges (in the 2D image) that are not parallel. When done correctly, this produces foreshortening (nearby objects are depicted larger than distant ones) and contributes to the illusion of depth.

Perspective is challenging to draw by hand, but Blender does it for you, provided you give it a 3D model of the scene and tell it where to view the scene from.

Blender only supports 3-point perspective, not 1-point or 2-point.

If you're confident you understand perspective, you can skip the rest of this module and proceed to the "Coordinate Spaces in Blender" module.

One-point Perspective

Figure 1: 1-Point Perspective.

Drawing classes teach various kinds of perspective drawing: one-point perspective, two-point perspective, and three-point perspective. In this context, the word "point" refers to what artists call the vanishing point.

When you're looking at a 3D object head-on and it's centered in your view, that is an example of one-point perspective.

Imagine looking down a straight and level set of train tracks. The tracks appear to converge at a point on the horizon. This is the vanishing point.

The image on the right is a 2D image of a cubic lattice or framework. Like any cube, it has six square faces and twelve straight edges. In the 3D world, four of the edges are parallel to our line-of-sight. They connect the four corners of the nearest square to the corresponding corners of the farthest one. Each of these edges is parallel to the other three.

In the 2D image, those same four edges appear to converge toward a vanishing point, contributing to the illusion of depth. Since this is one-point perspective, there is a single point of convergence at the center of the image.

Two-point Perspective

Figure 2: 2-Point Perspective.

Now the cube is at eye level, and you're near one of its edges. Since you're not viewing it face-on, you can't draw it realistically using one-point perspective. The horizontal edges on your left appear to converge at a point on the horizon to the left of the cube, while those on the right converge to the right. To illustrate the cube with a good illusion of depth, you need two vanishing points.

Three-point Perspective

3-Point Perspective.

Now imagine you're above the cube near one of its corners. To draw it, you'd need three vanishing points, one for each set of parallel edges.

From that perspective, there are no longer any edges which appear parallel. The four vertical edges, the four left-right edges, and the four in-out edges each converge toward a different vanishing point.

Additional Resources

• Perspective (graphical) at Wikipedia.

Coordinate Spaces in Blender

Figure 1: Objects in a three dimensional space. In the center of the coordinate system is the origin of the global coordinate system.

We'll start looking at how 3D scenes are represented in Blender.

As was explained in the "3D Geometry" module, Blender represents locations in a scene by their coordinates. The coordinates of a location consist of three numbers that define its distance and direction from a fixed origin. More precisely:

• The first (or x-) coordinate of the location is defined as its distance from the YZ plane (the one containing both the Y and Z axes). Locations on the +X side of this plane are assigned positive x-coordinates, and those on the -X side are given negative ones.
• Its second (or y-) coordinate is its distance from the XZ plane, with locations on the -Y side of this plane having negative y-coordinates.
• Its third (or z-) coordinate is its distance from the XY plane, with locations on the -Z side of this plane having negative z-coordinates.

Thus the origin (which lies at the junction of all three axes and all three planes) has the coordinates (0, 0, 0).

Global and local coordinates

Blender refers to the coordinate system described above as the global coordinate system, though it's not truly global as each scene has its own global coordinate system. Each global coordinate system has a fixed origin and a fixed orientation, but we can view it from different angles by moving a virtual camera through the scene and/or rotating the camera.

Global coordinates are adequate for scenes containing a single fixed object and scenes in which each object is merely a single point in the scene. When dealing with objects that move around (or multiple objects with sizes and shapes), it's helpful to define a local coordinate system for each object, i.e. a coordinate system that can move with, and follow the object. The origin of an object's local coordinate system is often called the center of the object although it needn't coincide with the geometrical center of the object.

3D objects in Blender are largely described using vertices (points in the object, singular form: vertex). The global coordinates of a vertex depend on:

• the (x, y, z) coordinates of the vertex in the object's local coordinate system
• the location of the object's center
• any rotation (turning) of the local coordinates system relative to the global coordinate system, and
• any scaling (magnification or reduction) of the local coordinate system relative to the global coordinate system.

For example, the teacup in Figure 1 is described by a mesh model containing 171 vertices, each having a different set of local (x, y, z) coordinates relative to the cup's center. If you translate the cup (move it without rotating it), the only bits of the model that have to change are the global coordinates of the center. The local coordinates of all its vertices would remain the same.

Coordinates of child objects

Figure 1b: A parent serves as the source of the global coordinates for its child object. The child is the cup; the parent's orientation is shown with the colored arrows.

Animation of the above

Any object can act as a parent for one or more other objects in the same scene, which are then referred to as its children. (An object cannot have more than one direct parent, but parent objects may themselves be the children of other objects.)

If an object has a parent, its position, rotation, and scaling are measured in the parent's local coordinate system, almost as if it were a vertex of the parent. i.e. the position of the child's center is measured from the parent's center instead of the origin of the global coordinate system. So if you move a parent object, its children move too, even though the children's coordinates have not changed. The orientation and scaling of a child's local coordinate system are likewise measured relative to those of its parent. If you rotate the parent, the child will rotate (and perhaps revolve) around the same axis.

Parent-child relationships between objects make it simpler to perform (and animate) rotations, scaling and moving in arbitrary directions. In Fig. 1b the teacup is a child object of the coordinate cross on the right. That cross is itself the child of an invisible parent. (It is both a parent and child.) In the cup's local coordinate system, it is not rotating, but as the cross on the right rotates around its Z axis, it causes the cup to rotate and revolve. In real animations, it will be much easier when the character holding the cup rotates, the cup changes its position respectively.

View coordinates

Figure 2: View coordinates and Projection Plane

Taking the viewer of the scene into consideration, there is another coordinate space: the view coordinates. In Fig. 2 the viewer is symbolized by the camera. The Z axis of the view coordinates always points directly to the viewer in orthographic projection. The X axis points to the right, the Y axis points upwards (Fig. 3).

Figure 3: View coordinates in viewing direction

In fact you always work in view coordinates if you don't set it any other way*. This is particularly useful if you have aligned your view prior to modeling something, e.g. if an object has a slanted roof and you want to create a window to fit in that roof, it would be very complicated to build the window aligned to the local coordinate system of the object, but if you first align your view to the slanted roof, you can easily work in that view coordinate system.

(* In the Blender 2.6 series, the default has been changed to global coordinates. View coordinates remain as an option.)

If you work in one of the three standard views (Front/Top/Side) the alignment of the view coordinates fits the global coordinates. Therefore, it is quite natural to model in one of the standard views and many people find this the best way to model.

Normal coordinates

Figure 4: Normal coordinate spaces for faces. The normal is shown in blue.

Although Blender is a 3D program, only objects' faces are visible. The orientation of the faces is important for many reasons. For example, in our daily lives it seems quite obvious that a book lies flat on a table. This requires the surface of the table and that of the book to be parallel to each other. If we put a book on a table in a 3D program, there is no mechanism that forces these surfaces to be parallel. The artist needs to ensure that.

The orientation of a face can be described with the help of the so-called surface normal. It is always perpendicular to the surface. If several faces are selected, the resulting normal is averaged from the normals of every single face. In Fig. 4 the normal coordinates of the visible faces are drawn.

This concept can be applied to individual points on the object, even if the points themselves have no orientation. The normal of a point is the average of normals of the adjacent faces.

UV Coordinates

In later parts (for example, talking about textures) you will come across coordinates labelled “U” and “V”. These are simply different letters chosen to avoid confusion over “X”, “Y” and “Z”. For example, a raster image is normally laid out on a flat, two-dimensional plane. Each point on the image can be identified by X and Y coordinates. But Blender can take this image and wrap it around the surface of a 3D object as a texture. Points on/in the object have X, Y and Z coordinates. So to avoid confusion, the points on the image are identified using U and V to label their coordinates instead of X and Y. We then refer to “UV mapping” as the process of determining where each (U, V) image point ends up on the (X, Y, Z) object.

Overview

Blender's user interface (the means by which you control the software) is not particularly easy to learn. However, it has improved over time and is expected to continue doing so. The current version of the Blender software is available for download from the Blender Foundation's website.

The tutorials in this section will familiarize you with the basics of the user interface. By the end of this section, you should be able to:

• resize, split, and merge any Blender window;
• change the type of any Blender window;
• access user preferences;
• access panels containing buttons and other controls;
• change the viewpoint of a viewport.

For those new to Blender, this is a fundamental section of the book.

Advice on Customization

Blender is a complex software package with many customizable features. You can customize the user interface to assign new functions to buttons and hotkeys. In fact, you can change almost anything to suit yourself. However, this complicates the giving and following of directions. It is recommended you adhere to the default screen arrangements of Blender in order to be able to follow the remaining parts of these tutorials. Blender ships with 4 to 5 screen-content arrangements which are suitable for almost any kind of job you'll want to use it for - from creating motion and animation to making games.

We recommend leaving Blender's user interface in its "factory settings" while working through the Noob to Pro tutorials. At the very least, wait until you've mastered the basics before you customize the interface — and we know you definitely will when you master it!

Keystroke, Button, and Menu Notation

As you read through these tutorials, you will encounter cryptic codes such as  SHIFT + LMB  and Timeline → End Frame. They describe actions you perform using the keyboard and mouse. The notation used in this book comes from the standard used by the Blender community. We will try to import those standards here to facilitate our studies.

If you're reading this book online, you may wish to print this page for future reference. In addition, or as an alternative, you can bookmark it in your browser for faster reference.

Hotkeys

A typical numpad

Most computer keyboards have number keys in two different places. A row above the letters, and in a numpad (numeric keypad) to the right of the keyboard. While many applications use these two sets of keys interchangeably, Blender does not. It assigns different functions to each set. If you're using a laptop keyboard without a separate numeric keypad, this might cause some difficulty. You'll need to use your function key to do some things. It is possible to indicate to Blender the type of keyboard you are using, but we strongly recommend you use a standard external keyboard if you use a laptop for these tutorials as it will make your studies and usage of Blender much more straightforward and enjoyable.

This book often assumes your keyboard has a numpad. If yours doesn't, consult the tutorial on Non-standard Input Devices for alternative ways to access the numpad's functions.

Key Notation

Notation	Corresponding key or action
Alt	The Alt key (known as ⌥ Option on Apple keyboards)
Cmd	The ⌘ Command key also known on other platforms as the ⌘ Windows key or ❖ Super key
Ctrl	The ⌃ Ctrl key (also known as the Control key)
Fn	The Fn key (also known as the Function key, generally found only on laptops)
Shift	The ⇪ Shift key
Enter	The ↵ Return key (also known as the Enter key)
Esc	The Esc key (also known as the Escape key)
F1  through  F12	The function keys F1 through F12 (often in a row along the top of the keyboard)
Space	The Spacebar
Tab	The ↹ Tab key
A  through  Z	The letters A to Z (on the keyboard)
0key  through  9Key	The digits 0 to 9, placed above the letters on the keyboard
Num0  through  Num9	The digits 0 to 9, placed on the numpad
NumLock ,  Num/ ,  Num* ,  NUM− ,  Num+ ,  NumEnter , and  Num.	The NumLock, /, *, -, +, Enter, and . keys respectively, all located on the numpad.
Delete	The Delete key
Down Arrow	The ⇣ Down Arrow key
Left Arrow	The ⇠ Left Arrow key
Right Arrow	The ⇢ Right Arrow key
Up Arrow	The ⇡ Up Arrow key

When a key is used in a module, it means press that key. For exammple:

•  M  means "press the M key"
•  Num0  means "press the 0 key thats found on the numpad."

Combinations that involve holding down a key while performing another action are written with a plus sign (+). For example:

•  Shift + Tab  means "press  Tab  while holding down  Shift "
•  Shift + Ctrl + F9  means "press  F9  while holding down both  Ctrl  and  Shift "

Mouse Notation

Blender uses three mouse buttons and the scroll wheel, if you have one. If your mouse only has one or two buttons, consult the tutorial on Non-standard Input Devices for alternative ways to access the functions assigned to these buttons.

Notation	Corresponding action
LMB	click with the Left Mouse Button
RMB	click with the Right Mouse Button
MMB	press down on (don't turn) the scroll wheel or Middle Mouse Button
SCROLL	turn the scroll wheel in either direction

Mouse and keyboard actions are often combined.  Shift + RMB  means to click  RMB  while holding down  Shift .

Navigating Menus

Blender uses both pop-up and pull-down/pull-up menus. Many menus have sub menus (menus that are reached via another menu). If a menu item displays a triangle, that means it leads to a sub menu.

The File menu

You can move through items in a menu by either:

• Moving the mouse pointer up and down

• Pressing  Up Arrow  and  Down Arrow 

You can enter a sub menu by either:

• Moving the mouse pointer to the right

• Pressing  Right Arrow  while hovering over a menu item that shows a triangle on its side.

You can leave a sub menu by doing one of the following:

• moving the mouse pointer to the left

• pressing  Left Arrow 

To initiate a menu action, you can:

• click  LMB 

• press  Enter 

You can escape from a menu by:

• moving the mouse pointer away from the menu

• pressing  Esc 

For each menu, Blender remembers your last choice and highlights it for you the next time you enter the menu.

Notation

Menu notation is fairly self-explanatory.

 Shift + A  Mesh → UV Sphere

Means:

1. Press Shift+A
2. In the menu that pops up, move through the items until Mesh is highlighted
3. Enter the Mesh sub menu
4. Move through the items until UV Sphere is highlighted
5. Press Enter or click the left mouse button to initiate the action

Additional Resources

• the Blender Manual page on "keyboard and mouse" at http://wiki.blender.org/index.php/Doc:Manual/Interface/Keyboard_and_Mouse

Non-standard Input Devices

This module is applicable only to users with non-standard input devices. If you have both a three-button mouse and a keyboard with a numpad, you can skip this module.

Keyboards lacking a numpad

Most modern laptops have a pseudo-numpad, a set of keys in the main keypad which double as a numpad. The keys typically used for this purpose are:

7key	8key	9key	0key
U	I	O	P
J	K	L	;
M	,Key	.Key	SLASH

When used as a pseudo-numpad, these keys typically act as the following keys from a true numpad:

Num7	Num8	Num9	Num/
Num4	Num5	Num6	Num*
Num1	Num2	Num3	NUM−
Num0	NumENTER	Num.	Num+

The numpad functions of these keys can often be toggled with  F11  or  NUMLOCK  on PCs or with  F6  on Macs. Alternatively, you can often temporarily activate the numpad behavior by holding down  Fn .

If your keyboard has the alternate labellings but you don't know how they work, consult your laptop owner's manual.

As a last resort, you can use the "Emulate Numpad" feature of Blender. This will allow you to use the normal numeric keys as if they were numpad numerics. Instructions for enabling this feature may be found in the "User Preferences Windows" module.

Blender uses the numeric keypad quite a bit. If you envision using your laptop for this kind of work, it may be worth investing in a USB Numeric Keypad. On eBay, prices for simple external numpads start around $10 USD.

Non three-button mouse

For single-button mouse users, make sure that Input for Blender 2.79 (under "User Preferences" on the left-most drop-down menu) → Emulate 3 Button Mouse is enabled.

On many computers with two-button mice,  MMB  can be emulated by simultaneously clicking  LMB  and  RMB . On Windows machines you'll need to enable this in the mouse settings in the Control Panel. On a Mac, open the Keyboard and Mouse preference pane and enable Use two fingers to scroll. Alternatively, by selecting Emulate 3 Button Mouse under User Preferences,  MMB  can be emulated by simultaneously clicking  Alt  and  LMB .

Recent IBM Thinkpad laptops allow you to disable the 'UltraNav' features of the middle mouse button in order to use it as a 'normal' third button. Alternatively, some laptops allow areas (called gestures) on the movement pad to act as  MMB  or  RMB , and these can be set up in the Control Panel in the Mouse Pointer options, selecting gestures and editing features there.

Apple single-button mouse

Apple single-button mouse substitutions

Notation	Single-button Substitute	Description
LMB	MB	the Mouse Button
RMB	Cmd + MB	Apple key + the Mouse Button
MMB	Alt + MB	Option (Alt) key + the Mouse Button

While Mac OS X natively uses both the  Ctrl + MB  and  Cmd + MB  to emulate  RMB , recent Blender releases for Mac OS X use only  Cmd + MB  for this purpose. This behavior is documented in the OSX Tips file that comes with the Mac version. You can also set the mouse to sense a right-click in System Preferences.

Note also that in the new, "unibody" design, the mouse button is under the trackpad, and the shortcut for  RMB  is clicking with two fingers simultaneously, which can be enabled in the System Preferences.

Laptops lacking a middle button but with a touchpad

Many laptops have touchpads. Touchpads, also known as trackpads or in some cases as smart-pads, can use gestures to give the effect of  MMB . The default for an Elan® Smart-Pad is two-finger tapping equivalent to clicking a  MMB . Dragging two fingers is the same as turning a mouse wheel.

Tablet PCs

To get the effect of  MMB  in a viewport, drag your pen around while holding down the  Alt  key.

Additional Resources

• version 2.4: keyboard and mouse (old documentation) — Blender 2.4 Manual

• Input devices (version 2.7x)

Operating System-specific Issues

This tutorial covers user-interface issues that are specific to particular operating systems or window managers. Read the section that applies to your computer; you may skip the rest.

GNU/Linux

 Alt + LMB  is used for changing the angular view on two angular axes of the 3D View window, if  Alt + LMB  moves the current window, then there's a conflict with your window manager. You can resolve the conflict or use  Ctrl + Alt + LMB  or  MMB  instead. (Also, you may have activated Compiz->Rotate Cube. Default configuration for rotating the Cube is also  Ctrl + Alt + LMB ; you may have to change this binding to an alternative configuration.) If you are running KDE this can be resolved by:  RMB  on the title bar of the main Blender window → select Configure Window Behavior → go to Actions → Window Actions → in the Inner Window, Titlebar and Frame section → select the Modifier key to be  Alt  and set all the select boxes beneath it to Nothing. An alternate method within KDE might be to  RMB  click on the title bar of the main Blender window; then select Advanced → Special Application Settings... → Workarounds and then click Block global shortcuts with Force selected and checked.

In Gnome, Click System → Preferences → Window Preferences. Look for the last three options Control, Alt and Super. Select Super. Or in Xfce, click Whisker → Settings → Window Manager Tweaks, and in the Accessibility pane, change Key used to grab and move windows to Super. Now you can press and hold  Cmd  or  ⊞  to drag windows around, and use  Ctrl  and  Alt  as normal.

KDE

Under KDE,  Ctrl + F1  through  Ctrl + F4  are by default configured to switch to the corresponding one of the first four desktops, while  CTRL + F12  brings up Plasma settings. You can change these in System Settings.

Alternatively you can suppress global shortcuts while inside blender by adjusting the kwin rules for this application, which you can access with a  RMB  click on the title bar of the window and pressing more actions->add program rule.

Gnome

You'll want to disable the Find Pointer functionality in Gnome, which will impair your ability to use certain functions such as Snap to grid and the lasso tool. If your mouse pointer is being highlighted when you press and release  Ctrl , go to: Mouse in Gnome's Desktop Settings and uncheck the box Find Pointer.

Ubuntu

As of Ubuntu versions prior to about 09.10 (“Karmic Koala”), there was a known incompatibility between Blender and the Compiz Fusion accelerated (OpenGL) window manager used in Ubuntu. By default, Compiz Fusion is enabled in Ubuntu, causing the problems to manifest themselves in Blender as flickering windows, completely disappearing windows, inconsistent window refreshes, and/or an inability to start Blender in windowed mode.

The fix for this is simple. Install compiz-switch (might be in universe). Go to Applications → Accessories → Compiz-Switch. This will disable compiz temporarily. Do the same to turn compiz back on when you're done using Blender.

This is no longer needed for current releases of Ubuntu.

Mac OS X

You may need to press  Fn  in order to use the  F1  through  F12  keys.

To expand a section in Blender, you would usually press  Ctrl + UpArrow . On a Mac, if “Spaces” is enabled, you may have to use  Ctrl + Alt + UpArrow .

Microsoft Windows

Two Ways to Launch Blender

Blender requires a console for displaying error messages, so if you launch Blender by means of an icon, two windows will appear: the graphical user interface plus a console window. Closing either window will terminate Blender. These windows are indistinguishable in the Windows taskbar in versions of Windows before Windows 7, which leads to confusion. Also, launching this way does not provide any way to pass command-line arguments to Blender.

Launching Blender from a command prompt is extra work, but it overcomes these issues:

1. Start → Run...
2. enter cmd
3. enter cd c:\Program Files\Blender Foundation\Blender
4. enter blender

Blender version 2.6 onwards doesn't have this problem, and hides the console window by default. You can show it by clicking Window > Toggle system console

Sticky Keys

Pressing  Shift  five times in a row may activate StickyKeys, an accessibility option which alters how the computer recognizes commands. If a StickyKeys dialog box appears, you should  LMB  the "Cancel" button.

If you don't need the accessibility features, you can disable sticky keys:

1. Start → Control Panel (OR search for "Accessibility Options" on the Start menu/Search)
2. double-click on Accessibility Options (Ease of Access Center in Windows 10)
3.  LMB  the Keyboard tab
4. for each of the options StickyKeys, FilterKeys, and ToggleKeys:
   1. clear the Use … checkbox
   2.  LMB  the Settings button
   3. uncheck the Use Shortcut checkbox in the settings
   4.  LMB  the OK button for the settings
5.  LMB  the OK button for Accessibility Options/Ease of Access Center.

Multiple Keyboard Layouts

On systems with multiple keyboard layouts, pressing  Shift + Alt  can alter the layout. (For instance, it might change from QWERTY to AZERTY or vice versa.) Because of this issue, Noob to Pro avoids  Shift + Alt  hotkeys.

If you find your keyboard layout altered, press  Shift + Alt  again to change it back.

You can also disable the hotkey:

1. Start → Control Panel
2. double-click on Regional and Language Options
3.  LMB  the Languages tab
4.  LMB  the Details button
5.  LMB  the Key Settings button
6.  LMB  the Change Key Sequence button
7. uncheck the Switch Keyboard Layout checkbox
8.  LMB  the OK button

Additional Resources

• Input method editor keyboard shortcut (CTRL+SHIFT+0) switches the input language in Vista — Microsoft Support Knowledge-Base
• StickyKeys at Wikipedia.

Blender User Interface

Here's a preview screenshot of Blender's interface, after a new installation.

Blender initial startup display

For those familiar with older versions of Blender, this will look very different. The redesign makes it much easier to find things.

For a detailed rationale explaining the redesign, read this.

Why does Blender use its own windowing system instead of the operating system's?

Blender follows its own user interface conventions. Instead of making use of multiple windows as defined by your particular OS/GUI, it creates its own “windows” within a single OS/GUI window, which is best sized to fill your screen. Many people accustomed to how applications normally work on their platform of choice, get annoyed by Blender’s insistence on being different. However, there is a good reason for it.

The essence of the Blender UI can be summed up in one word: workflow. Blender was originally created by a 3D graphics shop for their own in-house use. Being a key revenue engine for them, they designed it for maximum productivity, speed and smoothness of operation. That means avoiding “bumps” that slow down the user. For example, windows never overlap, so there’s no need to keep reordering them. You don’t have to click in a window to make it active, just move the mouse. There is a minimum of interruption from popups asking for more information before performing some action. Instead, the action is immediately performed with default settings, which you can adjust afterwards and get immediate feedback on the results.

Blender may not be “intuitive” to start learning, in that you cannot simply sit down in front of it and figure out things on your own, especially from a position of knowing nothing at all. But once you have picked up some basic conventions, you will find it starts to make sense and then you will be free to experiment and discover things on your own.

"Save changes on exit" prompt

As of Blender version 2.79, you are prompted on exit when there are unsaved changes. You can change this behaviour in Edit → Preferences → Save & Load → Save Prompt.

Prior to that version, Blender was not asking about unsaved changes. Instead, Blender saved changes, when it closes, to a file called 'quit.blend'. The next time you use Blender, you had to select File → Recover Last Session to resume right where you left off.

Blender Windowing System

The Blender user interface may appear daunting at first, but don't despair. This book explores the interface one step at a time.

In this module, you'll learn about Blender windows:

• recognizing windows and their headers,
• the different types of windows,
• how to activate and resize windows,
• how to split and join windows.

You'll also practice launching and leaving Blender.

An Interface Divided

Blender's user interface is divided into rectangular areas called windows (or sometimes, areas). The overall arrangement of windows is called a workspace.

If you haven't already launched Blender, go ahead and do so. You should soon see something that resembles the following.

Blender has had some major changes to its user interface (UI) since version 2.4x. Some of these changes include moving buttons and changing the space bar hot key from the “add menu” to the “search menu” ( SHIFT + A  is now the "add menu” hot key). This is important to know when trying to follow tutorials.

Other changes include the addition of the tool bar and window splitting widget. The shelf widget (indicated by a plus sign) opens hidden tool shelves. The object tool shelf can be toggled on and off by pressing  T . The properties tool shelf can be toggled on and off by pressing the  N . The split window widget allows you to split and join windows. Blender 2.69 is shown below.

If you see something substantially different...

• You may be running a different version of Blender - perhaps a newer version. The screenshot was made using the 2.69 release.

If you're running an older version, you should probably upgrade. Download instructions are in the Introduction.

• The user-interface settings on your computer may have been changed.

  Try resetting the user interface with File → Load Factory Settings.

To take a video in Blender, press  Alt + F3 , and click Make Screencast. This will record what's on your screen until you click the red Close button on the info header. The screencasts will be saved in the tmp folder. In Microsoft Windows, the tmp folder is located at 'C:\tmp'.

Window Headers

Did you find all five headers?

Every Blender window has a header. A header can appear at the top of the window, at the bottom of the window, or it can be hidden. Let's take a closer look at the headers.

The header of the Info window is outlined in green.

The header of the 3D View window is outlined in red. Note that it runs along the bottom of the 3D View window, not the top.

The header of the Properties window is outlined in blue.

The header of the Outliner window is outlined in white.

The header of the Timeline window is the one on the bottom (not outlined)

If you click with  RMB  on the header, a menu pops up which lets you move the header (to the top if it’s at the bottom, or vice versa), or maximize the window to fill the entire workspace:

To hide the header completely, move the mouse to the edge of the header furthest from the edge of the window (i.e. the top edge of the header if it is at the bottom of the window, or vice versa); it will change into a vertical double-headed arrow. Now click with  LMB  and drag towards the window edge, and the header will disappear. In its place, you will see the following symbol appear at the corner of the window: . Click this with  LMB  to bring the header back.

Window Types

Blender has many types of windows (there are 16 of them in Blender 2.69) and a Console for the Python programming language. You've just encountered the Info, 3D View, Properties, and Outliner windows. The rest will be introduced as needed in later modules.

Every window header in Blender has an icon at the left end to indicate the window type. For instance:

• = Info
• = User Preferences
• = 3D View
• = Outliner
• = Properties

If you  LMB  on the icon, a menu will pop up. (If you don't know what  LMB  means, please review the Keystrokes, Buttons, and Menus Notation module.)

By matching the icon in the header to the icons in the menu, you can tell that the window here is a 3D View window.

The menu can be used to alter a window's type. In this screenshot, the user is about to change the window into a Properties window.

Any window can be changed to any type. Blender doesn't mind if there are multiple windows of the same type.

The workspace layout is saved along with the document. Anybody subsequently opening the document will see the last-saved layout.

If you've changed any window's type, please change it back (or reload the factory settings with File → Defaults → Load Factory Settings) before continuing with this tutorial.

The Active Window

The active window is the one that will respond if you press a key. Only one Blender window is active at any given time.

The active window is usually the one containing the mouse pointer. (Blender uses a "focus follows mouse" user interface model. When a hotkey fails to work as expected, it is often because the mouse pointer has strayed into a neighboring window.) To change the active window, simply move the mouse pointer into the window you wish to activate.

Practice changing the active window by moving your mouse between the 3D View and the Timeline windows. The Timeline window is directly below the 3D View header. At this point, it's worth mentioning that the header for the 3D View window and Timeline window is at the BOTTOM of its own window instead of the top as the name "header" implies.

When a window becomes active, its header gets brighter.

Resizing Windows

Resizing windows is easy.

Dragging on a Border

Step 1

Move the mouse pointer to the border between two windows (the area outlined in red below. The pointer will change to an up/down arrow.

Steps 2-4

Press and hold  LMB .
Drag with the mouse to move the border up and down.
When the border is where you want it, release  LMB .

Whenever you increase the size of one window, you decrease the size of another. That's because Blender has a non-overlapping window interface: unlike many other programs, it does not permit windows to overlap. Neither does it move windows; it just resizes them. If you find that you cannot increase the size of a window (e.g. the Info window) any further although there seems to be enough space to do so, it may be because you decreased the size of another window (e.g., the Outline window) to its minimum size (i.e, just the heading).

Maximizing a Window

Another way to resize a window is to maximize it. When Blender maximizes a window, it makes the window as large as possible. The previous window configuration is saved.

• To maximize the active window, press  Ctrl + UpArrow  ,  Ctrl + DownArrow  or  Shift + Space . On a Mac, if “Spaces” is enabled, you may have to use  Ctrl + Alt + UpArrow .
• When a window is maximized, use  Ctrl + UpArrow  ,  Ctrl + DownArrow  or  Shift + Space  to restore the previous (unmaximized) window configuration.

Practice maximizing and un-maximizing the 3D View and Timeline windows.

If you are running a version of Blender before 2.57, you cannot maximize a User Preferences window.

Shelves

You will notice that the 3D View window (the largest window in the screenshots above) has several buttons down the left side. This rectangular portion is called the Tool Shelf. This is like a window within a window - you can drag the boundary between it and the main part of the 3D View to resize.

If you drag all the way to the window boundary, the shelf will disappear. In its place, the following symbol will appear: . Click it to bring the shelf back.

Too Much To Fit

If a window or shelf contains too much information to fit within its display area, scrollbars will appear along the bottom or right edge. You can scroll the contents by dragging these with  LMB ; alternatively you can drag with  MMB  directly within the contents.

A window header may also contain more than fits within its displayable area. There is no explicit visual clue for this (though some of the widgets at the right edge might not be visible), but if that happens, you can drag sideways within the header with  MMB  to scroll its contents.

Splitting And Joining Windows

At the top right and bottom left of every window, you will see something like this: . If you move the mouse over the icon, you will see the pointer turn into a cross. At that point, you can do one of the following by clicking and dragging with  LMB :

• Split the window into two copies horizontally by dragging horizontally away from the edge.
• Split the window into two copies vertically by dragging vertically away from the edge.
• Join the window to the adjacent one horizontally (getting rid of it and taking over its space) by dragging towards it.
• Join the window to the adjacent one vertically (getting rid of it and taking over its space) by dragging towards it.

Of course, the last two are only possible if there is in fact another window in that direction. Note: you can only join windows horizontally that are the same height, and windows vertically that are the same width.

The Default Workspace

If you look at the above screenshot of the default workspace, you will see the following window types:

• The menu bar at the top (outlined in green) is actually a window, called Info . In previous versions of Blender, you could resize this to reveal the User Preferences, but in 2.5x they have been moved to their own window type. Instead, all you can see here if you enlarge the window are some debug messages, which may be removed in a future version of Blender. As of 2.70, the debug messages are still present in this menu.
• The largest window on the screen is the 3D View . This is where you work on your model.
• The Properties window is the tall area on the right; this is where most of the functions are located for performing operations on models, materials etc. In previous versions of Blender this was called the Buttons window. Over time, it evolved into a disorganized area that made it difficult to find things. It has been cleaned up significantly in 2.5x. Note that it defaults to a vertical layout, rather than the horizontal one of previous versions. The new design prefers a vertical layout, which better suits today’s widescreen monitors.
• The Outliner (at the top right) gives you an overview of the objects in your document. As your models get more complex, you will start to appreciate the ability to quickly find things here.
• The Timeline (across the bottom) becomes important when you’re doing animation.

The default layout may not be optimal. For example, if you’re doing a static model or scene, not an animation, you can get rid of the Timeline. If you’re doing heavy script development, you’ll probably want the Console available to try things out. And so on.

Workspace Presets

In the Info window/titlebar, you will see a menu with an icon like this . Clicking on it with  LMB  will show the following menu:

Selecting from this menu lets you quickly switch between various predefined workspace layouts, tailored to various workflows. Try it and see. You can return to the default layout by selecting “Default” (but note that any changes you make to the layout are immediately associated with the name being displayed here). The menu has a search box at the bottom. Typing text here will restrict the menu to showing items containing only that text. It might not appear to have much use, but in a complicated project that needs dozens of different layouts, the search function could become very useful indeed!

The name of the currently selected item appears to the right of the menu icon. In the illustration above, this is "Default". Blender allows you to rename the current menu item by clicking on it with the  LMB  and typing a new name, so take care not to do so unless you actually want to rename the menu item. For example, if you replace the name "Default" with "MyDefaults", you will subsequently see that "MyDefaults" appears in the list of menu items.

Note also the “+” and “X” icons to the right of the menu; clicking “+” creates a new entry which is a duplicate of the last-selected entry, while clicking “X” gets rid of the currently-selected entry. You will see these conventions appear consistently in menus elsewhere in Blender’s new, revamped interface.

One Document At A Time

Blender can only work with one open document at a time (this does not apply to blender 2.79, which allows multiple instances of blender to run concurrently). To save changes to the current document, select one of the Save options from the File menu (or press  Ctrl + S  to save under the last-saved name). To open a new document (actually load a copy of your last-saved user preferences), select “New” from the File menu (or press  Ctrl + N ), and select “Reload Start-Up File” from the popup that appears, but be aware this will not automatically save any changes to the previous document.

Scenes

A scene is like a separate Blender-document within-a-document. Different scenes within the same document can easily share objects, materials etc. You can define them once and make different renderings and animations from them. You create, delete and switch scenes using the scene menu in the info header. A new document starts by default with just one scene, called “Scene”.

Leaving Blender

To exit Blender:

1. If there's a tool active, press  Esc  to exit the tool.
2. Press  Ctrl + Q . This brings up an OK? menu.
3. Confirm Quit Blender by clicking  LMB  or pressing  Enter .

In versions before 2.79, Blender will not prompt you to save your work. However, you can easily pick up where you left off by using File → Recover Last Session.

Additional Resources

• YouTube video on Splitting and Joining Windows in 2.49 at http://www.youtube.com/watch?v=uYb1j8X-ulc
• YouTube video on Splitting and Joining Windows in 2.59 at http://www.youtube.com/watch?v=mGK1gwFhx9M

• the Blender Manual page on "window types" at http://wiki.blender.org/index.php/Doc:Manual/Interface/Window_types
• the Blender Manual page on "changing window frames" at system/Arranging frames http://wiki.blender.org/index.php/Doc:Manual/Interface/Window system/Arranging frames

User Preferences Windows

A screenshot of the Blender Preferences window in Blender 2.80

In this module, we'll take a closer look at the Blender Preferences window.

Accessing Blender Preferences

To open the Blender Preferences window click Edit → Preferences...

In Blender 2.79, you will find it under File → User Preferences...

Configuring Your Preferences

In order to get to modeling and rendering sooner, this tutorial will cover only a few of the many user-settable preferences.

If you ever need to restore Blender to its factory settings, click File → Defaults → Load Factory Settings

Save & Load → Auto Save

As the name suggests, Auto Save automatically saves the current .blend after a specified period of time. You can turn this on and off using the checkbox labelled "Auto Save". You can also adjust the amount of time between each save, by adjusting the "Timer (Minutes)" field.

System → Undo Steps

By default, Blender remembers your last 32 actions and allows you to undo them one at a time by either pressing  Ctrl + Z  or by selecting a frame under Edit → Undo History. However, you can change the number of Undo Steps stored to remember more or less actions, in case you want to conserve memory or simply stay on the safe side. You can also use the Undo Memory Limit slider to specify the amount of RAM (in megabytes) used for storing the undo levels. In case you're not too worried about memory, you can set the Undo Memory Limit field to 0 to remove the memory limit.

Input → Numpad Emulation

Blender uses numberpad keys (such as  NUM7 ) to control the 3D View and ordinary numeral keys (such as  7 ) to change layers. If you are working on a laptop or if you find the numberpad inconvenient, you can select Emulate Numpad to reassign the 3D View controls to the ordinary numeral keys.

Input → Emulate 3 Button Mouse

Blender makes significant use of all three buttons on a standard computer mouse. If you do not have a mouse with three buttons, enabling this setting will let you perform  MMB -related actions with  ALT + LMB 

Keymap

In Blender 2.79 and earlier, Blender used right click for selection. However, in Blender 2.8, this was changed to left click on default, along with some changes to keyboard shortcuts for efficiency. To stay compatible with different users' preferences, three keymap presets are provided on installation: "Blender", the new default keymap, "Blender 27x", which includes very few changes compared to earlier versions, and "Industry Compatible", designed to be used by those coming from other 3D software, such as Maya and ZBrush

Since much of this book was written before the 2.8 update came out, you may find pages that still use the old "right click to select" option, along with some outdated keybinds. If you're following a lot of tutorials for Blender 2.79 or earlier, you can go into Keymap and select Blender 27x under the presets list. You can always switch back if needed.

Additional Resources

• The Blender manual pages on Preferences
• The tutorial on Non-standard Equipment describes other workarounds for numpad issues.

Properties Window

The properties window lets you change many settings and properties relating to the current scene and selected objects. You can edit many options, including customizing materials and textures, controlling how your scene is rendered and at what quality, among many other things.

The properties window is divided into categories, which themselves group individual tabs. Each tab, in turn, groups a selection of properties and settings. For example, the World Properties tab, under the Scene category, lets you control the color and texture of the background of the scene (i.e. the sky), and allows you to add volumetric effects to the scene (i.e. fog or mist). Each tab has their own, unique, icon. Some tabs will even change depending on the type of object selected!

Active Tool and Workspace settings

Active Tool and Workspace settings

As the name suggests, this simply configures the active tool (for example, the move tool) and various workspace settings (such as switching to object mode when a workspace is opened).

Scene

Render Properties

This tab lists settings that control the how the resulting render of a scene is displayed, such as performance-related settings, color management settings, and effects like motion blur. These settings will change depending on the render engine used, which can also be edited from this tab

Output Properties

This tab controls various settings that determing the output of a render. This includes resolution, frame rate, file format, among other

Scene Properties

This tab lets you choose which camera to use for rendering, change the units and edit the gravity settings for the current scene.

You can also select another scene to be a “background” for this scene. That is, all renders of this (foreground) scene will also include the contents of the background scene, as though they had been copied into this scene. While the background appears in the 3D viewport when editing this scene, none of its contents are editable, or even selectable; that has to be done in the background scene itself.

World Properties

This lets you change the environment of the scene. In this tab, you can edit the background color and texture (i.e. the sky color), and add volumetric effects such as fog or mist.

Collection

Collection Properties

This tab lets you control various collection settings, such as whether its contents are selectable, or whether it can be seen in render.

Object

Object Properties

This tab lets you control general object properties, such as transformations (i.e. location, rotation, scale), parent-children obejct relationships, collections, and other. Note that even if you have multiple objects selected, these properties only control the active object, which is usually the last object selected.

Modifier Properties

This tab lets you add, edit, and remove modifiers. Object modifiers are operations that affect your object in a non-destructive way (i.e. it can always be reversed later). For example, adding the bevel modifier to a cube applies a bevel to the geometry of the cube, but you can adjust the bevel or remove the bevel whenever you like. Some object types, such as lights and cameras, can't have modifiers.

Visual Effects Properties

This tab lets you add visual effects to grease pencil objects, such as pixelation and blur effects. These effects treat the object like an image. Unlike modifiers, these can not be applied to the object.

Particle Properties

This tab lets you add particle systems to objects, which can let you create effects such as smoke, flames or sparks. Particles in Blender can also be used to generate hair or fur. Particles can be set to custom objects, to produce effects like blades of grass, water droplets on a wet surface, or even entire buildings to make up a large cityscape!

Physics Properties

This allows you to simulate real-world physics, such as simulating solid dice colliding with each other, or simulating how water in a cup reacts when you move it.

Object Constraint Properties

Constraints limit various object properties, such as the location, rotation, and scale of the object. These are usually to set animate objects, such as making the wheels of the bus rotate together.

Object Data

Object Data Properties

These control settings specific to the object type such as text font, lamp settings, and camera settings. This is reflected in the icon, which changes according to the type of object selected.

Object Shading

Material Properties

The material settings for an object control its appearance, e.g. its colour, whether it has a shiny or dull surface, how transparent it is, and so on.

You can also control the material of an object using shader nodes.

Texture Properties

Textures in Blender used to control the surface of an object, alongside the materials. Nowadays, it has been replaced by the shader nodes, and is only used for texture painting.

3D View Windows

3D View windows are used to visualize 3D scenes. You’ll do a lot of work in these windows, so you will need to learn your way around.

The 3D view only shows an approximation of the final appearance of the scene. The overall geometry should be correct, but don’t expect accurate rendition of materials, textures, lighting etc, since that can be very time consuming. The 3D view is designed to respond to your actions at interactive speeds. There are additional view options (wireframe, hiding etc) that make it easier to see which parts of the model you’re working on, have no effect on the final render. You can change your viewpoint at any time (which will be essential while working on your model/scene), while the viewpoint of the render is controlled by the camera position.

In this module, you'll learn:

• to recognize 10 things commonly seen in viewports
• to tell which mode Blender is in
• how to change viewport options and viewpoints
• how to position the 3D cursor

You'll also learn the fundamentals of:

• visibility layers

The Viewport and its Contents

Aside from its header, the remainder of a 3D View window is its viewport. You use viewports any time you need an up-to-date view of the scene you're working on.

Viewports are busy places. Go on a scavenger hunt and see what you can find in a simple viewport.

1. Launch Blender.
2. Just so we're all looking at the same scene, load the factory settings using File → Defaults -> Load Factory Settings.
3. Confirm the “Load Factory Settings” popup with  LMB  (or  Enter ).
4. If the NumLock indicator on your keyboard is unlit, press  NumLock  so that numpad hotkeys will work properly.

(If you're unsure what  LMB  means, please review the Keystroke, Button, and Menu Notation module.)

You should see something like this:

Here the viewport has been outlined in red to focus your attention on it.

A Virtual Scavenger Hunt

Look at the default scene and find the following eight items:

In the Center

1. a solid gray cube with orange edges.

• This is the default cube, your first Blender object!

2. Three arrows, one red, one green and one blue, their tails joined to a white circle

• This is not an object (part of your model/scene), but part of Blender’s user interface for manipulating objects. It is the manipulator, also known as the 3D transform widget.
• The arrows represent the directions of the X, Y and Z axes of the currently chosen transform orientation coordinate system. Initially this is the global coordinate system.
• The circle represents the center of the selected object (the cube).
• If you don't know what the "global coordinate system" is, please review the module on Coordinate Spaces in Blender.

If you don't see the manipulator...

• It's possible that a tool is active. Press  Esc  to cancel any tool action.
• Another possibility is that the manipulator has been disabled:
  • Toggle it on or off with  Ctrl + Space .

3. A red-and-white striped circle with black cross-hairs

• This is not an object. It is the 3D Cursor, which indicates where newly-created objects will appear in the scene.
• The cursor is similar to the insertion point in a text editor, which indicates where new text will be inserted in a document.

In the Lower Left Corner

4.

• This is not an object. It is the mini axis, and its orientation matches that of the global coordinate system, with the usual conventions: red for X, green for Y and blue for Z. Think of it as a little compass, reminding you which way is left/right, front/back and up/down.

5. The notation "(1) Cube"

This is not an object. It is object info, indicating that:

• You're viewing the first frame of an animation.

and

• The current or most recently selected object is named "Cube".

In the Upper Left Corner

6. The notation “User Persp”

This is not an object. This tells you which mode the viewport is in. The first word will change if you select one of the perfect views or the camera view (see below), otherwise it just says “User”, and the second word is “Persp” or “Ortho” to indicate whether this is a perspective or orthographic view.

To the Right of Center

7. A black round thing that resembles a sun symbol

This represents a lamp, a light source for the scene. (It is an object.)

8. A pyramidal wireframe item

This represents a camera, a viewpoint that can be used for rendering. (It too, is an object.) The camera is looking at the base of the pyramid. The solid triangle attached to one side of the base is to remind you which way is up in the image that the camera takes.

On a small display, the camera might initially lie outside of the viewport and thus be invisible. In that case,  SCROLL  to zoom out until it becomes visible.

Throughout

9. A dark gray background, divided into squares by lighter lines. This is the grid floor, which you can (but don’t have to) use as a ground plane for positioning your models.

Each grid square is one blender unit (or BU) on a side. A BU can be whatever you wish, e.g. an inch, a centimeter, a mile, or a cubit. Blender lets you choose your scene scale in the Scene tab of the Properties Panel.

10. Three mutually perpendicular coloured lines associated with the grid floor: the red and green ones lying horizontally in the floor and the blue one running vertically. These are the global coordinate axes for orienting your scene. Red is the X-axis, green the Y-axis, and blue the Z-axis.

• In Blender 2.67a, you can't see the blue line for Z-axis here, but you can see it in Front or Side view.

Modes

Blender has many modes, i.e. settings that affect its behavior, and this is especially true of the 3D View window.

Sometimes it's not obvious which mode is active. This leads to mode errors where Blender will do something you didn't expect because you thought it was in one mode and it was actually in another.

The function performed by a hotkey or mouse button can depend on:

• what mode the user interface is in,
• whether the keyboard is in NumLock mode,
• which window is active,
• the mode the active window is in,
• which item or items are selected,
• whether you've initiated a hotkey sequence.

It helps to recognize the common modes and how to get out of them.

Object Mode vs. Edit Mode

The 3D View windows are normally in Object Mode. In this mode:

• • The mouse pointer is the default arrow normally used on other programs.
  •  RMB  is used to select objects in the scene.
  • In versions 2.8 and above Use  LMB  to select objects in the scene

If there are objects in the scene, you can get into five other modes:

• Edit Mode: used to edit the shapes of objects
  • The mouse pointer is a thin inverse-video cross.
  •  RMB  is used to select vertices, faces or edges of the current object.
  • Press  Tab  to enter/exit this mode.
• Sculpt Mode/Vertex Paint/Texture Paint/Weight Paint
  • The mouse pointer is now a thin, orange (white in Texture Paint) circle.

These modes are also indicated by a menu in the 3D View header. You can use this menu to change modes.

These modes are a setting shared by all 3D View windows. In other words, when you change the mode in one window, any other 3D View windows change mode also.

Viewport Options

The options in this section only affect 3D View viewports. They do not affect renders.

Solid vs. Wireframe

By default, the 3D View window draws objects using the Solid drawtype, in which surfaces are opaque. To toggle between Solid and Wireframe drawtype (edges only, no faces) for a particular viewport:

1. Activate the 3D View window

1. Press  Z .

Alternatively, you can choose these and other drawtypes from the "Viewport shading" menu in the 3D View window header.

Orthographic vs. Perspective

By default, viewports draw orthographic views. To toggle a viewport between orthographic and perspective views:

1. Activate the 3D View window.
2. Press  Num5 .

(If you're unsure what the difference is, please review the "Orthographic Views" module and the "Perspective Views" module.)

Note this perspective versus orthographic setting for the 3D viewport is completely separate from the similar setting in the camera properties. The former takes effect while you’re working on the model, the latter when you render.

So why have a separate setting for the 3D view? Because certain aspects of modelling are easier in one view than another. If the final render will be using perspective, then showing perspective in the 3D view naturally gives you a better idea of how the final render will look. But perspective foreshortening can sometimes make it hard to ensure the model has the proper shape, which is why there is the option to switch to orthographic view.

If you have trouble distinguishing between orthographic view and perspective view

... you should activate the View Name option. This is enabled by default and causes the name of the current view ("User Persp", for instance) to appear in the upper left corner of every viewport. If there is no text, then you can enable it by:

1. Accessing the User Preferences window.
2. Click on the Interface tab.
3. Enable View Name.

Changing Your Viewpoint, Part One

Each viewport has a viewpoint, which takes into account:

• the location of the viewer in the 3D scene (There doesn't need to be an object at that location.)
• the direction the viewer is looking
• the magnification (or zoom factor) used

Changing your viewpoint allows you to navigate your way through a 3D scene.

We'll start with three very basic techniques:

• Zooming
• Orbiting/View Rotation
• Perfect Views.

Additional techniques will be covered later in this module.

Zooming

Blender offers several ways to zoom in and out:

• Use  SCROLL 
• Click and drag vertically with  Ctrl + MMB .
• Use  Num+  and  NUM−  to zoom in and out in small increments.

Note the following limitations of Blender's zoom feature:

• If the viewport is in orthographic mode, Blender zooms as if looking through a telescope. You can increase the magnification, but the viewpoint's location doesn't change. For this reason, you cannot zoom into or through objects in orthographic mode.
• If the viewport is in perspective mode, Blender zooms to the center of the viewport. The viewpoint can pass through objects, but can't pass beyond this point, no matter what you do. Zooming only gets slower and slower and slower. If the center of the viewport is somewhere you don't expect, zooming may appear to be broken.

Orbiting and View Rotation

Let's fly around the default cube, viewing it from different angles. In this way you'll see that it really is a cube, centered on the origin, half above the X-Y plane and half below it.

1. Activate the 3D View window by placing the mouse pointer inside it.
2. Now you can:
   • Click and drag with  MMB  to orbit freely around the center of the view.
   • Use  Shift + Alt + SCROLL  to rotate the viewpoint vertically around the center of the view.
   • Use  Num2  and  Num8  to rotate the viewpoint vertically around the center of the view in 15-degree increments.
   • Use  Ctrl + Alt + SCROLL  to rotate the viewpoint around the Z axis.
   • Use  Num4  and  Num6  to rotate the viewpoint around the Z axis in 15-degree increments.

If this is all very confusing for you, don't worry! You'll learn as you get more experience.

When you are finished flying around the cube, you can restore the original view by reloading the factory settings with File → Load Factory Settings.

If the hotkeys don't work...

You may have pressed number keys above the letters instead of the ones on the numpad. If you do, the default cube will vanish. This is because the scene consists of multiple layers. The default cube is in layer 1, and you've told Blender to switch to the layer of the number you just pressed. The selected object (the cube in this case) remains in layer 1, which is no longer visible. For instance,  2Key  tells Blender to switch to layer 2. To switch to layer 1 again, press  1Key . You can view the different layers by clicking on the little squares on the layer map:

User comments

The Shift + Alt + Scroll and Ctrl + Alt + Scroll do not work for me with factory settings in Blender 2.92.0 (Doesnt Work Counter: 2.People)

The center of the viewport is not marked, i.e. it's difficult to tell where it is. This can cause unexpected behavior during rotation.

Perfect Views

It's often useful to get a perfect view of a scene, i.e. to view it along one of the main axes, with the other two main axes oriented up-down and left-right.

Perfect View Hotkeys

Hotkey	View	Axis Pointing Right	Axis Pointing Up
Num7	"top"	+X	+Y
Ctrl + Num7	"bottom"	+X	-Y
Num1	"front"	+X	+Z
Ctrl + Num1	"rear"	-X	+Z
Num3	"right side"	+Y	+Z
Ctrl + Num3	"left side"	-Y	+Z

The following screenshot shows all three perfect views plus camera perspective for the Suzanne primitive:

This layout is used so often, it has a keyboard shortcut: ( CTRL + ALT + Q ).

Positioning the 3D Cursor

Positioning the 3D cursor is a very basic operation, yet one that many beginners find challenging. It touches on an issue common to all 3D graphics software: "How do you specify points in a 3D scene when we can only see two dimensions at a time?"

Basic Technique

1. Go into either Object Mode or Edit Mode.
2. Move the mouse pointer to the desired position (in any viewport).
3. Click  SHIFT + RMB .

Two Challenges

Challenge #1. Using only tools presented thus far, try positioning the 3D cursor on the virtual camera.

Try it!

When you're done, check your work by orbiting the camera.

Perhaps you thought you were done when you clicked on the camera. But the moment you changed your viewpoint, you probably found that the 3D cursor was actually behind (or in front of) the camera.

Hints:

• Try positioning the cursor in two different perfect views.
• Use orthographic, not perspective, view.

Challenge #2. Using only tools presented thus far, try repositioning the 3D cursor at the origin (that is, at the center of the cube).

As before, check your work by orbiting the cube. Don't spend too much time on this.

User Comments

"I found that I would select the cube when left clicking on it in object mode, if the "Use 3d transform manipulator" button was enabled. To toggle this off, you click on the gray pointing hand in the 3d panel header, or (Ctrl Space)."

"When you want the cursor back into the cube, just select the camera with RMB, put the cursor into the cube following the steps above, and re-select the cube with RMB."

"I've discovered it helps a lot if you are in Object Mode and not in Edit Mode. I wrote the following before discovering this: The problem with this exercise, for me, is that left clicking on the cube selects the cube instead of moving the 3d cursor. If I click on the cube outside of its central white circle I can get the cursor to move there, but only to outside of this white circle, and even then this only works sometimes."

"I failed at this until I had zoomed in close enough to the cube. When I was too far zoomed out I kept selecting the cube rather than creating an edit point."

"I had the same problem and found it was because the cube was selected. I made sure I was in object mode, right clicked on the camera to select the camera instead of the cube, and I could then position the edit point in the cube. However, doing this messed up the next part of the tutorial because you cannot switch into edit mode with the camera selected! Perhaps the suggestion of trying to put the 3D cursor in the cube should be dropped as it raises too many questions at this stage."

"You can deselect all by pressing the AKEY or the select button in the 3D View."

"Use wireframe mode works better to get the cursor in."

"To get it back in the cube: 1) Make sure you're in object mode. 2) Select the cube. 3) Object > Snap > Cursor to selection (cursor refers to the 3D cursor here) so it puts it right in the middle of the cube."

"I think it's an essential point to note that in order to place the cursor inside the cube, the cube must NOT be selected. AKEY was probably the best way to deselect the object."

"If I remember correctly, undo history gets cleared when you switch between object and edit mode."

"I wasted a lot of time here. Thank you to the reader who suggested (on the 3D view header) Object > Snap > Cursor to selection. It was the only thing that worked to get the cursor visible again and placed where clicked."

"I missed the point of the exercise first time around. You can't set a 3D point on a 2D screen without technique. Orthographic views are crucial. I am just learning, but take that, at least, away from it."

"Positioning the 3D cursor in othographic views always made it snap to the cube surface, making it impossible to center precisely. Fix this by disabling "Cursor Depth" on the "interface" tab under "User Preferences".

"The phrase check your work by orbiting the camera needs additional clarification, such as a referenced section or the precise commands to use."

More Ways to Position the Cursor

Here's an easy way to position the cursor at the center of an object:

1. Make sure Blender is in Object Mode, with the object selected.
2. Move the mouse pointer to any 3D View window.
3. Snap the cursor to the selected object using either:
   •  Shift + S  → Cursor to Selected

   or

   • Object → Snap → Cursor to Selected

Here's 2 easy ways to relocate the cursor to the scene's origin (0, 0, 0):

1. Move the mouse pointer to any 3D View window.
2. Press  Shift + C  to reset the cursor to the origin.
   • Note that this also changes the view location, meaning that when you zoom in, you won't zoom in to the scene origin.
3. A better way is to click Object → Snap → Cursor to Center
   • You can also do this by  Shift + S  → Cursor to Center.

Changing Your Viewpoint, Part Two

Now you'll learn some additional techniques for obtaining the view you want:

• Panning
• Centering
• Jumping to the camera's viewpoint
• Zooming in on a selected area

Panning

When you orbited the cube, the viewpoint's position and direction both changed at the same time. You also can shift the viewpoint up-down or left-right without changing its direction. (This is similar to the side-scrolling effect in the classic Mario and Sonic video games.)

This is called panning, and it's an important skill to master. Try it now:

1. Activate a 3D View window by placing the mouse pointer inside it.
2. Now you can:
   • Use  Shift + SCROLL  to pan up and down.
   • Use  Ctrl + Num2  and  Ctrl + Num8  to pan up and down in small increments.
   • Use  Ctrl + SCROLL  to pan left and right.
   • Use  Ctrl + Num4  and  Ctrl + Num6  to pan left and right in small increments.
   • Click and drag with  Shift + MMB  or  Shift + Alt + LMB  to pan freely in the viewplane.
     

You will likely find this to be a distraction in some cases. To move the viewpoint position back to the center, snap the cursor to the center, then click View → Align View → Center View to Cursor. You could also snap the cursor to the center then press  Ctrl + Num. .

In versions ≥2.74 you can also use  Alt + Home  to center the view to the cursor.

Centering

When you zoom or rotate the view, you always zoom or rotate around the center of the view.

To make sure everything in your scene is visible:

1. Press  Home .

To center the view on an arbitrary point:

1. Move the 3D cursor to the point of interest.
2. Verify the cursor position from a second viewpoint.
3. Press  Alt + Home  to center the view.

To center the view on an object in the scene:

1. Make sure Blender is in Object Mode.
2. Zoom out until the object is in the viewport.
3. If any objects are selected, use  A  (or Select → Select/Deselect All) to deselect them.
4. Select the object of interest by clicking  RMB  on it.
5. Press  Num.  to center the view.

Jumping to the Camera's Viewpoint

To see the scene as the virtual camera sees it, press  Num0 . Afterwards, you can rotate, pan, and zoom normally, but the virtual camera will not follow. To go back to your previous view, press  Num0  again. (In the latest versions of Blender, the virtual camera can be made to follow all the changes made in viewpoint while in camera view by checking the option "Lock Camera to View" on the Transform panel. Hit  N  on your keyboard to bring up the transform panel. To disable this option uncheck "Lock Camera to View.")

Zooming into a Selected Area

Suppose you want to get an extreme closeup of a particular area. Because there's no center mark on the viewport, you might have to pan and zoom several times to get the desired view.

The shortcut for zooming to an area is:

1. Activate a 3D view window that contains the area of interest.
2. Press  Shift + B . A crosshair appears in the viewport.
3. Click and drag with  LMB  to draw a rectangle around the area of interest.
4. When you release  LMB , the viewport will zoom in on the area you selected.

View Navigation

You can also change your viewpoint in the 3D view by “walking” or “flying” through it. To activate this, press  SHIFT + F . By default in Blender 2.70, this puts you in “walk” mode. Earlier versions only offered “fly” mode. (In Blender 2.70 and later, you can choose which one you prefer in User Preferences, under the Input tab.)

In both modes, helpful prompts appear in the header of the 3D view window to remind you of the key functions while the mode is in effect. When you have reached the position and orientation you want, press  LMB  or  ENTER  or  SPACE  to end the navigation mode and stay there, or  RMB  or  ESC  to abandon the navigation mode and be teleported immediately back to your original position and orientation. (In 2.77+, pressing  SPACE  will teleport you to where the cross hairs point towards.)

Walk Mode

In this mode, you move the mouse to turn your view up/down/left/right, and  W ,  A ,  S  and  D  or the corresponding arrow keys to move forward, left, back or right, and  E  and  Q  to move up or down respectively. Hold a movement key down to keep moving. Movement stops as soon as you release it. Pressing  MMB  will “teleport” you close to whatever objects lie within the crosshairs at the centre of the view.

You can also use  TAB  to turn on gravity. Make sure there is a floor or other object under you to land on! With gravity on, you can no longer use the vertical movement keys, but you can use  V  to make jumps. Press  TAB  again to turn gravity off.

Fly Mode

In this older mode, moving the mouse to change the view works the same as in Walk mode, but the above direction keys ( W ,  A ,  S ,  D ,  E ,  Q  and the arrows) apply “thrust” in the respective directions, so you keep moving after releasing the key. Press the key repeatedly to increase your speed in that direction, or press the key for the opposite thrust direction to reduce your speed. You can roll the mouse wheel up to apply forward thrust, or roll it down to apply backward thrust.

Your current velocity vector automatically changes direction with you when you turn. Thus, you can apply a single burst of sideways thrust while facing an object, then, without applying any additional thrust, keep turning to face the object, and you will go right around it.

Visibility Layers

Every object in the scene is assigned to one or more of 20 visibility layers.

Visibility layers have many uses:

• You can put scenery, characters, particles, and lamps in different layers, to help organize your scene.
• By changing which layers are visible, you can simplify your view of the scene and work with only one or two layers at a time.
• When rendering, only visible layers are included. You can use this to render your scene layer by layer, checking each layer separately.
• You can configure lamps to illuminate only objects in the same layer.

Left: Viewing layer 1 only.
Right: Viewing all 20 layers.

In Object Mode, you can tell which layers are visible by looking at the twenty small boxes located in the 3D View header between the Transform Orientation menu and the "Lock" button. The top row of boxes represents layers 1 through 10, with 1 being the leftmost and 10 being the rightmost. Similarly, the bottom row of boxes represents layers 11 through 20.

Hotkeys

• To view just one of layers 1 - 9, press  1KEY  ..  9KEY .
• To view just layer 10, press  0Key .
• To view just one of layers 11 - 19, press  ALT + 1KEY  ..  ALT + 9KEY 
• To view just layer 20, press  ALT + 0KEY .
• To toggle the visibility of one of layers 1 - 9 without affecting the visibility of the other layers, press  SHIFT + 1KEY  ..  SHIFT + 9KEY .
• To toggle the visibility of layer 10 without affecting the visibility of the other layers, press  SHIFT + 0KEY .
• To toggle the visibility of one of layers 11 .. 19 without affecting the visibility of the other layers, press  ALT + SHIFT + 1KEY  ..  ALT + SHIFT + 9KEY .
• To toggle the visibility of layer 20 without affecting the visibility of the other layers, press  ALT + SHIFT + 0KEY .
• To make all layers visible at once, press  ~ . Press  ~  again to return to your previous layer visibility setting.

The hotkeys in this section will not work if you've enabled numpad emulation in the User Preferences window. See the "User Preferences Windows" module for more details.

Note to AZERTY users:

On the AZERTY keyboard layout, the standard number keys are the &é"'(-è_çà keys. Do not use  Shift  unless you want to toggle visibility as explained below.

Holding down  Shift  while selecting a layer (by keyboard or mouse) will, instead of making only that layer visible, toggle the visibility. In this way, you can select combinations or to hide particular layers.

The key to press to select all layers at once differs by keyboard layout. It is:

•  ¬'  (the key under Esc) on UK keyboards,
•  `~  US,
•  ö  German, Swedish, Finnish and Hungarian,
•  ¨  Swiss German,
•  æ  Danish,
•  ù  AZERTY,
•  ø  Norwegian,
•  Ñ  Spanish,
•  ç  Portuguese,
•  "  Brazilian Portuguese,
•  ò  Italian, and
•  ё  Russian.

After pressing the aforementioned key, holding down  Shift  while pressing it again will restore the visibility settings you had before you made all layers visible.

When only one layer is selected, new objects are automatically assigned to that layer. When two or more layers are visible, new objects are assigned to the most recently visible layer.

Count Your Polys

If you want to count the polygons in your scene, the data is available in the Info Header.

As you can see in the above image, this scene has 507 vertices and 500 faces (polygons).

Object Mode

Introduction

In this module, you will learn some basics about operating in Object mode. This is normally the default mode Blender is in when you open a new document. It is the mode where you operate on whole objects, rather than on their parts.

Many of the conventions involving selection and manipulation of objects or parts of objects apply to other modes as well, so this is a good place to become familiar with those conventions.

Cube selected in Object mode.

Open a new document, then confirm you are in Object mode by checking the mode menu.

Select the default cube by clicking on it with  RMB . You will see it framed in an orange outline.

Object Origin

When you select an object, you will notice a round dot appears, normally in the middle of the object, the same orange-yellow as the rest of the selection.

This is the object’s origin. It is the reference point for the object’s local coordinate system. Certain kinds of edits to the object can cause this origin to end up at a position well outside the object. If that happens, operations like transformations applied with reference to the origin may not behave as expected. However, Blender has capabilities to deal with this. They will be explained when you need them.

Multiple Selections

You can select more than one object at a time. With the cube still selected, change your view until you can see both the cube and the default lamp. Select the lamp by clicking on it with  SHIFT + RMB  (  SHIFT + LMB  for versions after 2.8), so both the lamp and the cube are selected. You will notice that the lamp takes on the orange-yellow colour, but the cube now has a more reddish highlight.

The active object is the last one selected. Other objects can be part of the selection, but the reddish-orange highlight indicates that they are not active. The Properties window shows properties for the active object, not the entire selection, although operations in the 3D view like moving and deleting objects will affect the entire selection. Some operations (like parenting, which you will learn about later) set up a special relationship between the active object and the rest of the selection, so for these, the order of selection of objects becomes important.

You can remove the active object from the selection with  SHIFT + RMB ; the small spot indicating the origin of the object’s geometry stays highlighted in the yellow-orange colour, even though the rest of the object loses the selection highlight. If you do this to an inactive object, it will make that object active.

Pressing  CTRL + I  inverts the selection. i.e. it deselects what was previously selected, and selects everything else instead. It does not change the active object.

Selecting Obscured Objects

If multiple objects lie under the mouse, you can choose which one to select by clicking  ALT + RMB : this will bring up a menu listing the names of the selectable objects.

Alternatively, you can add an object to the current selection, or remove it from the current selection, by clicking  ALT + SHIFT + RMB  and selecting it from the menu.

On Ubuntu 16.04 LTS, it appears that  ALT + RMB  has the same effect as  RMB  on a Window's title bar. But  ALT + SHIFT + RMB  does the trick of Selecting Obscured Objects.

Selecting Everything and Nothing

Pressing  A  does one of two things: if anything is selected, it clears the selection (i.e. selected objects are no longer selected). But if nothing is selected, then it selects everything. You will often see instructions to press  A  either once or twice, to ensure that either nothing is selected, or everything is selected.

Hiding Things

When working on a complex model or scene, things are likely to get cluttered, making it hard to see the specific part you’re working on. It is possible to hide objects, so they no longer appear in the 3D view. Select the object(s) you wish to hide, and press  H . This is purely a convenience for working in the 3D view, i.e. hidden objects remain unchanged when you render them.

Pressing  SHIFT + H  hides everything except the current selection. This is a quick way to remove the clutter and narrow the view to the objects of interest.

Pressing  ALT + H  brings back all hidden objects and selects them. If you lose track of what is hidden and what is visible, press this to bring everything back.

Local Versus Global View

Local view is another way of selectively hiding parts of the scene. Pressing  NUM/  ( \  for emulated numpad) hides everything that is not selected, and automatically zooms in or out as necessary so the selected objects fill the 3D view. Pressing  NUM/  again, restores the items to the normal global view.

This differs from simple hiding with  H  in that a render done in local view only shows the objects currently visible in that view. In particular, if your lights are excluded from the local view, you are liable to see black blobs in place of your objects.

How do I determine the viewing mode? Look at the words in the upper-left corner of the 3D view. They indicate your current view orientation and perspective settings (e.g. “User Persp”). If the word “(Local)” appears at the end of the string, you are in local view. Otherwise, you are in global view.

Border Select (Box Selection)

A quick way to select many objects at once is with the Border Select (box selection). Press  B  to activate it. You will see a pair of dotted crosshairs appear centred at the current mouse position. Drag diagonally with  LMB  to mark a selection rectangle, then release the  LMB . Everything within the rectangle will be added to the selection. If you didn't mean to engage box-selection mode, pressing  ESC  exits border select mode.

Alternatively, to remove things from the current selection, after pressing  B , drag the selection rectangle with  MMB . When you release the mouse button, everything in the drawn box will be deselected.

Circle Select (Brush Selection)

Another way to select several objects at once is with the Circle Select (brush selection), engaged by pressing  C . In this mode, clicking or dragging on objects with  LMB  adds them to the selection, while  MMB  removes them from the selection. Thus the mouse becomes a brush that you can use to “paint” objects in or out of the selection.

The circle showing the size of the brush can be adjusted with the mouse wheel. This allows you to use a broad brush for selection of lots of objects at once, or a finer one for better control.

Clicking  RMB  or pressing  ESC  terminates Circle Select mode.

The Manipulator

Manipulator transformation buttons & orientation menu

Manipulator—translation

Manipulator—rotation

Manipulator—scaling

The manipulator appears in the middle of the selection. There are three kinds of manipulator as shown in the illustrations. It can be used to apply translation (position changes), rotation, and scaling (size changes) to objects. Its appearance changes according to which of these functions are enabled. You can click on the menu transformation buttons that appear when the manipulator is visible, to choose a single transformation, or shift-click to enable more than one simultaneously. You can toggle the visibility of the manipulator with  CTRL + SPACE , or by clicking the menu button with the red, green and blue arrows.

If you have troubles selecting the red arcs of the rotation manipulator select File→ User Preferences... System → Selection and change it to "OpenGL Select" or "OpenGL Occlusion Queries".

Transform orientations: the “Orientation” menu governs how the axes of the manipulator are aligned, with the default “Global” corresponding to the global coordinate system. Other useful options are “Local”, which corresponds to the local coordinates system of each object, and “View”, which is always aligned to your view.

To demonstrate this, click on the camera with  RMB  so that it is the only object selected. Set the manipulator to do only translations (blue arrow button is selected in menu), and ensure the orientation is set to “Global”. Drag any of the manipulator's coloured arrows with  LMB  to move the camera in the corresponding direction.

Now switch the orientation to “Local”. You will see the manipulator arrows re-orient themselves. Note that the Z-direction (blue arrow) is now in the direction of the camera view. The local co-ordinates of the camera have the optical axis of the camera running along the Z axis. By default, that is pointing towards the cube object.

The cube, by default, has its own local Z-direction running vertically.

With the manipulator orientation still set to Local, add the cube to the selection with  SHIFT + RMB . You will see the manipulator move so it is in the centre of the selected objects. It is now between the camera and the cube. Now if you drag the manipulator Z axis arrow with  LMB , each object will move along its own version of that axis. The camera moves towards or away from the cube and the cube rises or falls.

Switch the orientation to “Global”, and try dragging a manipulator arrow again. This time, both objects will appear locked together and will move in the same direction, along the same (global) axis.

Transformation Hotkeys

The manipulator is not the only way to apply transformations to objects. That can also be done via keyboard shortcuts.

Hide the manipulator to reduce clutter. Select the cube, and only the cube, with  RMB . Now press  G  to Grab the object. The selection outline around the object turns white, as it did when you were dragging with the manipulator, except this time, you didn't press any mouse buttons. Now move the mouse without pressing any buttons, and you will see the object move along with it. Press  LMB  or  ENTER  to terminate the movement and leave the selected object at the new position, or  RMB  or  ESC  to cancel the operation and leave the object at its original location.

Similarly, use  R  to Rotate the object, and  S  to Scale it.

You can constrain the movement to particular axes by pressing the appropriate axis key. For example, press  G  to start moving the cube again, then press  X  and you will see a bright colored line appear parallel to the global X-axis. Now when you move the mouse, the cube will move along only that colored line. Similarly  Y  and  Z  constrain movement to the Y and Z axes respectively. The colored lines that appear are a brighter reddish, green or blue that correspond to the red, green or blue lines for the X, Y or Z axes, respectively.

Transform orientations: to constrain the transformation to a different set of axes, press the constraint key twice. The coordinate system used depends on the selection in the Transform Orientation menu:

• Local or Global — the transformation happens in the object’s local coordinate system.
• View — the transformation is aligned to view coordinates.

For example, with the default “Global” selection from this menu, select the camera with  RMB , press  G  to move it, then press  Z  twice, and you will see the coloured line orient itself along the direction of view of the camera.

The axis constraints also work with scaling, and rotation (which only happens around the specified axis).

You can also constrain movement and scaling to happen along two axes, but not the third one, by holding down  SHIFT  when typing the axis constraint. For example,  G  followed by  SHIFT + Z  will constrain movement to the global X-Y plane (i.e. any direction except along the Z-axis). To constrain movement to the local X-Y plane, type the contraint twice:  G   SHIFT + Z   SHIFT + Z .

Here's a summary of what the transformation hotkeys do, with and without constraints:

Key	without constraint	followed by axis	followed by  SHIFT -axis
G	moves in plane perpendicular to view direction	moves along axis	moves in plane perpendicular to axis
R	rotates about view direction	rotates about axis
S	scales uniformly along all axes	scales along axis	scales uniformly in plane perpendicular to axis

In addition, the hotkey sequence  R   R  enables free rotate, i.e. the object can rotate around all three axes as you move the mouse.

Transforming by Numbers

Sometimes you need to position things accurately, using calculated numbers, instead of estimating by eye. Blender can do that too. Simply type the number after the transformation hotkeys before pressing  ENTER  to confirm the operation. For example,  G   X   1KEY   ENTER  will move the selection by 1 unit in the positive X direction.  G   X   −KEY   1KEY   ENTER  will move by 1 unit along negative X. Decimal points are allowed, thus  S   0KEY   .KEY   5KEY   ENTER  will scale the selection by a factor of 0.5, or 50%.

Rotation works similarly, using degrees clockwise around the selected X, Y or Z axis.

Transformation Menu

Yet another way is shown at right, in the Transform panel that appears at the top of the Properties shelf (press  N  to toggle its visibility at the right side of the 3D view). Here you can see the existing transformations values. You can drag the sliders to change them, or click on them and enter new values.

Choosing the Pivot Point

When you do a scaling or rotation operation, you can choose the pivot point, which is the central origin point that remains unaffected by the operation. By default this is the “Median Point”, or centre point of the selection, but the Pivot Point menu lets you choose some other options. For example, select both the cube and the camera, and rotate them ( R ). By default they will rotate around their common centre. Now go to the Pivot Point menu and choose “Individual Origins” and rotate your two selected objects with  R  again, and you will see each one now rotates about its own centre, rather than the common one.

Another useful pivot option is “3D Cursor”, which places the transformation origin at the 3D cursor location.

Finally, the button with three dots and a double-headed arrow immediately to the right of the one that pops up the Pivot Point menu is titled “Manipulate center points.” Selecting this means transformations do not rotate the actual objects themselves, only their positions. To see the effect, you need to choose a pivot point that is not the object’s origin. Now try rotating the object. You will see its centre describes an arc around the pivot point, without changing the object's orientation. Think how the seats in a Ferris Wheel rotate around the wheel's pivot, yet still maintain their orientation.

Similarly scaling will change the distance between the chosen pivot point and the object’s origin, but will not affect the size of the object itself. A bursting firework scales rapidly in this way.

Why can't I rotate or scale objects? One pitfall you might encounter is that you select an object, try rotating with  R  or scaling with  S , and nothing happens, though moving with  G  still works. It's quite likely you have the “Manipulate center points” button active when you didn't mean to. Check if it's active, and click it to deactivate if so.

Hotkeys — there are keyboard shortcuts for all the above options:

Pivot Option	Key
Active Element	ALT + .KEY
Median Point	CTRL + ,KEY
Individual Origins	CTRL + .KEY
3D Cursor	.KEY
Bounding Box Center	,KEY
Toggle Manipulate Center Points	ALT + ,KEY

Basic Camera Technique

The camera view  NUM0  is very useful for making adjustments to your camera while getting continuous feedback on how the render will look. This view shows a framing rectangle covering the area that will appear in the render, surrounded by a passepartout which gives a darkened view of the surrounding part of the scene. You can use the mouse wheel to zoom in and out, adjusting how much of your view is the rendered area and how much is passepartout.

In this view, use  RMB  on the framing rectangle to select the camera, and it will show the usual orange-yellow highlight. The manipulator will not appear even if enabled, so you must use the transformation hotkeys to perform camera transformations.

Use  G  to move the camera around parallel to the view plane. Since the view stays locked to the camera, you will see the scene move in the direction opposite of what you might expect.

The camera’s local Z-axis lies along its direction of view. This allows useful operations like  G   Z   Z  to move the camera in or out without affecting the direction in which it's pointing. Also the X axis runs left to right in the camera view so rotating around X  R   X   X  will adjust the up-and-down pitch angle. Rotating around the vertical Y axis  R   Y   Y  will change the yaw (left-right) angle, and you can rotate around the optical axis of the camera using  R   Z   Z  to produce an effect of rolling the view around the visual axis.

Another useful technique is to position the 3D cursor at a point of interest, set the pivot point to the 3D cursor, then rotate the camera about a global axis, like the global Z-axis ( R   Z ), to adjust the angle of view while keeping the same objects in view, and without altering the distance of the camera from the point of interest. In real life you'd get that effect by walking in a circle around your subject with your camera mounted on a Steadicam rig.

Scaling the camera object changes its size as shown in the 3D view, but has no effect on the actual render. Regardless of what axis constraints you try to apply, the camera object will always scale uniformly along all axes.

You can also use Fly mode  SHIFT + F  in camera-view mode to fly around the scene, taking the camera with you.

Another choice for moving your camera in Camera View is to bring up the Properties panel ( N ) and, in the View section, tick the box next to Lock Camera to View. Now you will be able to use the  MMB  to "move objects" just as you move things around in other views such as the 3D view. Holding down the  MMB  and dragging will rotate,  Shift + MMB  will allow you to "move the object" around in the view (panning), and the scroll wheel will allow you to "move the object" closer or farther from the camera. You are actually moving the camera with these manipulations and not the object(s) themselves.

Scaling the Camera: You can scale the camera object with  S  as you can most other objects. However, this has no effect on what is seen with that camera. Think of it as strictly a cosmetic thing to make the camera object easier to spot (if it's too small relative to other objects in the scene), or scale it down to keep it in proportion when working with smaller objects. Another way of changing the displayed size of the camera is to look in the Camera data context in the Properties window, in the Display panel. Here there is a Size field that you can use to increase or reduce the size of the camera

Adding/Removing Objects, Undo/Redo, Repeat

Select the cube with  RMB  again. Press either  X  or  DEL  and, after confirming the popup, the cube disappears! It has been deleted from your scene. Unlike mere hiding, it really has disappeared. Press  CTRL + Z  to undo your last operation, and it reappears.

Click with  LMB  to position the 3D cursor away from the default cube. Press  SHIFT + A  to bring up the Add menu, go to its Mesh submenu, and add another cube to the scene. Again, undo with  CTRL + Z , and you are back to a single cube again.

Now press  CTRL + SHIFT + Z : this will undo the undo, and redo the last operation you undid, bringing back the second cube.

Try adding a third cube. Now  CTRL + Z  should undo that and take you back to two cubes, and pressing  CTRL + Z  again should undo the addition of the second cube, taking you back to one. Try  CTRL + SHIFT + Z  at this point to restore the second cube, then  CTRL + SHIFT + Z  again to restore the third one.

Blender remembers up to the last 32 things you did (depending on the limit set in your user preferences) in its undo stack. You can go backward and forward through it with  CTRL + Z  and  CTRL + SHIFT + Z .

Sometimes you want to perform an action repeatedly. To repeat the last action, type  SHIFT + R .

Assigning Layers

Earlier, you learned about showing and hiding layers in the 3D view. To assign layers for selected objects, press  M . The same keyboard shortcuts apply here as when choosing which layers to display, i.e.  1KEY  for only the first layer,  2KEY  for only the second etc,  SHIFT + 1KEY  to include/exclude the first layer and so on.

After assigning an object to a different layer, it disappears! If this happens to you, it's because the layer(s) you assigned to the object, and the layer(s) you currently have visible in the 3D view, have nothing in common. Simply change the visible layers to include at least one of those you assigned the object to, and it will reappear. For example, if currently only layer 1 is visible, and you assign an object to only layer 2, it will disappear, but reappear when you change the visible layer to layer 2.

Object, Action, Settings

Bring up the Add menu again ( SHIFT + A ). This time, add a new cylinder mesh to the scene. Look to the left of the 3D view, in the Tool Shelf (toggle its visibility with  T  if it's not visible), at the bottom you should see a new panel has appeared, titled “Add Cylinder”. Near the top of it is the “Vertices” number, initially defaulting to 32, which gives a fairly round-looking cylinder. Reduce it to 6, and adjust the view as necessary to get a good view of your “cylinder”, and you will see it is now a hexagonal prism. Change the number of vertices to 3, and it becomes a triangular prism.

This is an example of an important user-interface convention that runs right through Blender: first you select the object you want to perform an operation on as appropriate (not applicable here because we are creating a new object), then you perform the specified action with some default settings, and finally you adjust the settings to give the exact result you want. This way, instead of getting a popup before the action is performed, into which you have to put the right settings and hope they will give the right result, you get to interactively adjust the settings and immediately see the results, without having to continually redo the operation and deal with popups.

Meshes and Edit Mode

A mesh is one of the most important and frequently-used object types in Blender. While there are other types of objects that can be used to model parts of a model or scene (text, NURBS patches, etc.), they often get converted to meshes at some point anyway, because it is the object type that offers the greatest amount of detailed control. And as it happens, Blender offers more functions, both built-in and available as addons, for dealing with meshes than for any other object type.

Edit mode is the mode in which you make changes to the internals of the active object. Not every object has an Edit mode (e.g. cameras), and the details of what you can do in Edit mode vary between the object types where it is available. This module specifically covers Edit mode for mesh objects.

What Is a Mesh?

A mesh is made up of one or more vertices; each vertex is just a point in space. A pair of vertices can be joined by a straight line called an edge, and a complete loop of edges can be filled in to form a face.

It is the faces that make up the visible surface of the object. The edges and vertices are essentially geometrical "scaffolding" necessary to hold the object together.

A face must have three or more sides (edges). Prior to version 2.63, only three or four sides were allowed, so faces had to be triangles or quadrilaterals (usually abbreviated to quads) respectively. Starting with v2.63, and the introduction of the BMesh architecture, that restriction has been lifted. You can have faces with 5 or more sides, but you will usually find that things work best if all faces, as far as possible, are quads. Particularly when constructing a model for animation purposes.

Blender’s Object-mode “Add” menu ( SHIFT + A ) contains a Mesh submenu with a collection of pre-made mesh objects. Think of these as starting points. They make building your own objects easier by enabling you to modify an object that is an approximation of the form you want instead of having to construct a mesh entirely from scratch.

Introduction to Edit Mode

Start a new model. Hide the manipulator if it is visible ( CTRL + SPACE ). You should be in Object mode. Click with  RMB  on the default cube to ensure it is selected and the active object.

The default cube in Edit mode

You can switch modes using the mode menu, as you previously learned. However, because switching between Object mode and Edit mode is such a frequent operation, it has a keyboard shortcut:  TAB . Do this now, and you should see the appearance of the cube change, as shown at right. The mode menu should also update. Press  TAB  again, and you should be back in Object mode. Press  TAB  once more before continuing, to ensure you are in Edit mode.

Note the following features of the cube, and how they relate to the description of a mesh above:

• The dots at the corners are the vertices.
• The lines joining them are the edges.
• The filled areas bordered by the lines are the faces.

Selection Modes

Select mode buttons in a 3D View header, showing Vertex select mode active. (Found below the edit area.)

In Edit mode, the header (it's at the top) of the 3D View window changes to show the selection-mode controls. If you hover over each of the buttons in the group of three, you will see they represent vertex-select, edge-select and face-select respectively. You can shift-click to enable more than one at a time.

In vertex-select mode, you select a single vertex by clicking on it with  RMB , and select more than one by shift-clicking on additional vertices with  RMB . Shift-clicking with  RMB  on an already-selected vertex will deselect it.

Pressing  A  will select all vertices if none are currently selected, otherwise it will unselect all vertices.

Edge-select mode works in a similar way, except with edges instead of vertices. Similarly, face-select mode will allow you to select and unselect faces.

The single button immediately to the right of these three is titled “limit selection to visible”. When it is active (the default), the mesh object being edited is displayed as opaque which means that vertices, edges or faces on the side away from you are hidden and cannot be selected. Click this button, and the object becomes translucent, allowing clicking through front faces to select parts of the mesh behind them.

Another useful display mode for working in the 3D view is wireframe, which can be selected from the Viewport Shading menu or toggled with the  Z  key. In this mode, the faces become transparent, almost invisible, and the edges and vertices are displayed more prominently.

Here is what these various selection and display modes look like in combination: in the first row, a single vertex is selected. In the second row, a single edge, and in the third row, a single face. In the first column, limit-selection-to-visible is enabled. In the second column, it is disabled, and in the third column, wireframe mode is enabled.

Selection Mode Hotkeys

You can also switch selection modes with  CTRL + TAB . In the menu that appears, you can switch to a single selection mode by selecting it with the mouse or up/down-arrow keys and pressing  ENTER  or  LMB . But if you press  SHIFT + ENTER  or  SHIFT + LMB  that toggles the enabling of only that selection mode, without affecting the state of the others, as does shift-clicking on the icons above.

In common with other Blender popup menus, you can quickly select an item from the  CTRL + TAB  menu and immediately confirm by pressing one of  1KEY ,  2KEY  or  3KEY  to select the first (vertex), second (edge) or third (face) item in the menu. Or,  SHIFT + 1KEY ,  SHIFT + 2KEY  and  SHIFT + 3KEY  while the menu is up, will toggle the enabling of vertex, edge, and face-select modes respectively.

Multiple Selections

You can use  SHIFT + RMB  to select multiple items, and  CTRL + I  to invert the selection, just like in Object mode. Only here, the “items” are vertices, edges or faces, depending on the selection mode in effect. The active (last-selected) part is shown in white, while the rest of the selection (if any) is drawn in the usual orange-yellow colour.

As mentioned above,  A  works similar to the way it works in Object mode, only instead of applying to everything, it applies to all parts of the object being edited.

Hiding Things

 H ,  SHIFT + H  and  ALT + H  work in a way analogous to their behaviour in Object mode. Again, instead of applying to everything, they apply to all parts of the object being edited.

Remembering What's Hidden: If you switch out of Edit mode with some parts hidden, they will reappear, then disappear again when you re-enter Edit mode, i.e. each object remembers what was hidden when you last edited it.

Local Versus Global View

You can toggle local/global view in Edit mode, as you can in Object mode. However, instead of narrowing the view to one or more selected objects, it narrows it to just the object being edited.

Border Select (Box Selection) & Circle Select (Brush Selection)

 B  and  C  work analogously to the way they do in Object mode, i.e. you select multiple items by drawing a box or by “painting” over them.

Select More, Select Less

Edit mode has some additional selection capabilities. To demonstrate them, let’s use something other than the default cube, for a change.  TAB  back to Object mode, and delete the cube. Now add ( SHIFT + A ) a Grid object.  TAB  into Edit mode, and you will see that the grid is made up of 9×9 faces, or 10×10 vertices. Initially they will all be selected. Use  A  to unselect them then  C  to brush-select a few vertices in the middle. End brush-select mode with  RMB  or  ESC . Now watch what happens to the selection when you press  CTRL + NUM+  (select more). Additional vertices adjacent to those already selected are added to the selection. Now try  CTRL + NUM−  (select less), and you will see the vertices on the edge of the selection are removed from it.

Manipulator, Transformation Hotkeys, Pivot Point

All of these are available for use in Edit mode as they are in Object mode, except for the “Manipulate center points” button.

Note that scaling vertices scales the distances between them. The vertices themselves have no size, so they do not get larger or smaller. Similarly, rotating vertices only changes their direction relative to the pivot point, since a featureless point itself has no orientation.

Transform Orientations

The Global, Local and View options in the Transform Orientation menu apply in Mesh Edit mode as they do in Object mode. In addition there is Normal mode, where the transformation axes are aligned relative to the selection:

• If a single face is selected, the X and Y axes are aligned along the face, while the Z axis is aligned perpendicular (normal) to the face.
• If a single edge is selected, the Z axis is aligned along the edge, with the X and Y axes perpendicular to it.

Other selections are also possible. Feel free to investigate their behaviour for yourself.

Thus, with a single face selected,  G   Z   Z  will move the face along its normal.

In addition, it is possible to define the current Normal transformation orientation as a custom orientation for use in transforming other vertices and even other objects. To do this, you need to go to the Properties Shelf, which is made visible on the right of the 3D view with  N . Near the bottom is the Transform Orientations panel which contains a Transform Orientation menu which looks the same as the one in the header of the 3D View window, except it also has a “+” button next to it. Click the "+" and the current Normal transformation orientation will be added to the menu initially labeled “Vertex”, “Edge” or “Face”, depending on what is currently selected (and with a unique numeric suffix added if there is already a custom orientation defined with that name). Now if you look in either Transform Orientation menu, you will see a new selectable item, in a separate section above the five standard items.

With your new orientation option selected, an editable text field will appear in the Transform Orientations panel, allowing you to change the name if you wish, and there is also a “X” button allowing you to delete the orientation item when you no longer need it.

With your new orientation option selected, you can now select a different part of the object, or even  TAB  into Object mode and select some other object. The manipulator and the doubled axis hotkeys will now align their transformations along this custom orientation. This is handy, for example, for aligning objects to a sloping plane.

Proportional Editing

When trying to produce natural, organic shapes, moving vertices one by one gets tedious. To produce smoother looking shapes, you need a mode where unselected vertices close to the selection also get some movement. In contrast to the sharp distinction between selected vertices which are moved and unselected ones that remain in place, there is a gradual transition from one to the other.

This is where proportional editing comes in. If you select “Mesh” in the header and examine the pop-up menu, you will see two submenus, titled “Proportional Editing” and “Proportional Editing Falloff”. The former toggles the mode on and off, the latter controls the falloff function choice. There is also an icon for “Proportional Editing” in the header of the default 3D view. Look to the right of the "Limit Selection to Visible" (on edit mode). The hot key is the letter O. Pressing  O  will toggle between Enable and Disable. Pressing  SHIFT + O  will change the Falloff type.

The “Proportional Editing” submenu has 4 options: “Disable”, “Enable”, “Projected (2D)”, and “Connected”. Do you still have the Grid object you created in the “Select More, Select Less” section above? If not, add a fresh Grid object. Switch to Edit mode, and ensure that just a few vertices in the middle are selected. Enable proportional editing, and now use  G  to move the selected vertices. You should notice 2 things:

• unselected vertices near the selected ones also move, and
• there is a white circle enclosing all the vertices that undergo any movement.

Try using the mouse wheel while moving the vertices, and you will see the white circle grow or shrink, and the proportional region of influence will grow or shrink correspondingly.

Try different falloff functions in the “Proportional Editing Falloff” submenu. Some ensure the mesh stays smooth and curvy, others give a more angular effect, etc.

The third option to "Disable" and "Enable" proportional editing is "Projected (2D)". This view is similar to enabled, except depth is ignored. The radius of the influence region is applied to the mesh two dimensionally.

The fourth option to “Disable” and “Enable” proportional editing is “Connected”. This one makes a difference in more complicated meshes, which might have folds or concavities in them. In this situation, “Enable” affects all vertices within a particular distance of the selected ones, while “Connected” only measures the distance via connected edges, rather than directly through space. This lets you move one part of the mesh without affecting another part which might be located nearby purely as a result of a fold.

Of course, proportional editing works with scale  S  and rotate  R  operations as well.

Deleting Things

Now let’s try deleting parts of a mesh. This is the menu that comes up when you press  X  or  DEL  when editing a mesh. For now, we will concentrate on the first three items.

First, go into face-select mode. Select one face of the default cube, press the delete key, and select “Faces”. As shown in the screenshots, the selected face should disappear.

Use  CTRL + Z  to undo your previous deletion. Now go into edge-select mode. Select one edge this time. Press delete again, this time select “Edges”. As the screenshots show, the selected edge disappears, but the faces bordering that edge also disappear. Faces cannot exist without their bordering edges!

Use  CTRL + Z  to undo your previous deletion again. Go into vertex-select mode. Select one vertex, make sure it's the one closest to you so you get the best view of the effect. Press delete, and select “Vertices”. Not only does the selected vertex disappear, but also the edges connected to that vertex. Edges cannot exist without their endpoint vertices. And since those edges disappeared, the faces dependent on them for their borders were deleted as well.

So, to recap:

An edge cannot exist without its endpoint vertices. A face cannot exist without its boundary edges. Hence, a face cannot exist without the endpoint vertices of its boundary edges.

Undo/Redo

You can undo your last Edit-mode operation with  CTRL + Z , and undo your undo with  CTRL + SHIFT + Z , similarly to Object mode. However, Edit mode maintains its own undo stack, separate from the Object-mode stack. To undo/redo an Edit-mode operation, you must be in Edit mode, not Object mode.

Adding Things

Back to the default cube and Edit mode. Ensure you are in vertex-select mode with nothing selected. Do a  CTRL + RMB  somewhere near the cube. Do you see a little orange-yellow dot appear where you clicked? You just added a new, unconnected vertex to the mesh. (If not, you may need to set this hotkey in user preferences -  CTRL + ALT + U  and search for "duplicate or extrude".)

Undo your addition ( CTRL + Z ). Select an existing vertex with  LMB . Now  CTRL + RMB  to add a new vertex again. You will notice that it is connected to the previously selected vertex by a newly added edge as well. Since the newly added vertex is now the selected vertex, doing  CTRL + RMB  again at another position, and so on repeatedly, lets you construct a whole chain of new edges. But what good are edges and vertices without faces?

To construct a face, you will need a closed loop of edges. To close a loop of edges, select all the vertices in the chain, and press  F . That will add another edge joining the first and last vertex into a complete loop of edges and fill in the loop with a new face.

If you want to close the loop without filling in the face, select only the first and last vertex in the chain before pressing  F . Since only two vertices are selected, a new face will not be added, i.e. it will only add an edge joining the two vertices.

You can also extrude new sections of mesh with a single click in this way. Try selecting two adjacent corner vertices of the cube (i.e. two joined by an edge). Now  CTRL + RMB  near them, and you will see you’ve created two more vertices, joined to the previous two by a new face.  CTRL + RMB  again, and you can construct a whole sheet of new mesh in this way.

Undo all your additions, and get back to the pristine cube. Now select all four vertices of a single face.  CTRL + RMB  near your selection, and you should have four new vertices (corresponding to the original four you selected), plus a new face connecting them, plus four new faces connecting them to the original four. (You may not have noticed it, but the face formed from the original four vertices has been removed as well.) Another  CTRL + RMB  does the same thing again. So with just a few clicks, you started with a cube and ended up with something (see at right) that is starting to resemble — who knows? A square-cross-sectioned piece of some wonky-looking pipe, perhaps?

Simplifying Things

It is possible to remove vertices without leaving holes behind in the mesh, by merging two or more vertices into one. Select the vertices you want to merge, and press  ALT + M ; a menu will pop up with some options, including whether to position the resulting vertex in the middle of the ones being merged, or at the position of the first or last one you selected. The resulting vertex inherits all the edges that were connected to the vertices being merged, as well as the faces connected between those edges.

Sometimes an operation creates duplicate vertices in exactly the same positions, or very close together. You can merge these en masse by ensuring you have selected all possible candidate vertices (e.g. the whole mesh), bringing up the Vertex Specials menu ( W ) and selecting the “Remove Doubles” item. Look for a message saying “Removed n vertices” to show briefly in the Info window. If n is 0, nothing was done. If you look in the lower left part of the Tool shelf, you will see a “Remove Doubles” panel has appeared, with a “Merge Distance” slider that governs the maximum distance allowed between vertices that are merged. Change this value as appropriate (either by clicking on the left and right arrows, or by clicking and typing in a new value and pressing  ENTER ), and the Remove Doubles operation is immediately redone. A new message will indicate how many vertices were removed. Simply keep adjusting the value until you are satisfied you haven't removed too many or too few vertices.

Normals and Shading

Open a new Blender document. Delete the default cube, and add a “UV Sphere” mesh. In the “Add UV Sphere” panel which appears at the lower left of the Toolshelf (press  T  to make the Toolshelf visible if it’s not), set both the Segments and Rings to a low number, e.g. 8. The result will be very angular, as shown to the right, not round like you would expect a sphere to be.

Press  F12  to do a quick render. The 3D view will be replaced with the UV/Image Editor view, showing the rendered image, as at right. Press  Esc  to return to the 3D view .

Select the sphere object ( RMB ). Now look in the Toolshelf for the shading buttons: , and click on “Smooth”. Now try a new render with  F12 .

As you can see, the surfaces of the object look a lot smoother and curved, even though the outline or silhouette is just as angular as before.

Return to the 3D view with  Esc . Ensure the UV sphere object is selected, and you are in Edit mode. Bring up the Properties shelf at the right side of the 3D view with  N  if it’s not already visible. Look for the Mesh Display panel, and find the settings for Normals. . If you check both icon boxes, the display of the UV sphere should change to look something like the image to the right.

Those spiky little lines are the normals; the green ones in the middle of each face are face normals, the blue ones protruding from each vertex are vertex normals.

In the physical theory of light, the normal is a line perpendicular to the surface of the object the light is hitting. When your eye (or the camera) C is positioned on a plane through the normal of a particular surface observing a certain surface point P illuminated by a coplanar light source L, a specific amount of light will be reflected and hence be registered by the camera depending on the physical characteristics of the surface. The observed intensity of reflected light is at a maximum if the angle C-P-L is divided into two equal halves by the normal.

In the real world, a lot of surfaces are curved or otherwise not flat. But a mesh can only be made up of straight edges and flat faces. So how can it represent an object with a curved surface?

When you added the UV sphere to your scene, you had the option of specifying how many segments and rings it was made from. The more of those present, the closer the geometry approximates a curve. However, the more there are, the longer the render will take, and the more memory the model will consume to hold information about all the extra vertices, edges and faces.

Which is where that “Smooth” shading button you clicked comes in. It applies a trick called Phong shading. Instead of doing the lighting calculation based on a normal for each face as the physical theory says you should, it starts with a normal assigned to each vertex, and interpolates the normal at each point on a face from the vertex normals at its corners, based on the distance at that point to those corners. The result fools the eye into seeing curved, rounded surfaces where there aren’t any.

This completely violates the laws of physics. To start with, how can you define a “normal” which is perpendicular to a point? But as you can see, the results look rather good, with relatively little extra computation involved, much less than actually generating all the extra geometry.

As you learn more about computer graphics, you will come across more tricks like this. Physically accurate modelling is still very difficult to do, even with modern computers, and the results may not look all that good. But by adopting a bit of lateral thinking that goes completely against physics, we can often, ironically, come up with much more realistic-looking results.

Not So Smooth?

If you have been adding lots of vertices, edges and faces to your mesh, you may end up with discontinuities in smooth shading causing unsightly blotches, as shown to the right.

Assuming your mesh is constructed properly (e.g. no edges and faces cross each other in physically impossible ways), the most likely reason for this is the normals in the newly added vertices and faces are pointing the wrong way. To fix it, select the troublesome part of the mesh (or select the whole thing) in Edit mode, and press  CTRL + N  to recalculate all the normals. Re-render the scene to confirm the shading discontinuity has disappeared.

Note the different meaning of  CTRL + N  in Edit mode. In all other modes, it opens a new default Blender document!