Blender 3D: Noob to Pro/Render Settings
|Applicable Blender version: 2.6x.|
The render settings control various options related to the output of rendered, or full quality images. Rendering an image will calculate effects not displayed in the editing environment (due to their complexity), and therefore takes a larger amount of time to produce an image. If you notice an error partway through a render, then you can pressto abort the render.
The Render Settings 
Let's take a look at all of the rendering options that Blender has. Open up a new scene (CTRL + N) and click on the camera icon in the Properties window to get to the rendering context. You should see something that looks like the image on the left.
These are the default settings for Blender Internal. Let's take a look at all of these settings and see what they do.
Render Layers and Render Passes 
Render layers are a way of organising data so that you can edit the render selectively after it's finished. This requires different objects to be on different scene layers, and each scene layer usually has it's own render layer (though this is arbitrary).
Render passes are different types of data that make up an image, separated and put into it's own 'pass' that you can use to change the render selectively. This is extremely common when using Blender's compositor to do post-processing.
For example, let's say that you want to composite a 3D object from Blender into a video that you shot. In order to make the shadows from the render affect the footage, you would enable ambient occlusion and select the 'AO' pass as shown in the image on the right. You then would have an AO pass in addition to the combined render. You could then multiply the AO pass over the footage in the compositor in order to make shadows from Blender appear in your footage. If you had separated your image into different color passes then you could edit each color pass to make the colors match the footage.
Of course, you could also use the render passes/layers to make post-processing easier in completely digital scenes. e.g. use the Index Object pass to make a glare effect on a particular object. The index object pass creates a greyscale mask for an object that you can plug into the 'Factor' input of the glare node, this makes the glare effect occur only for that object.
Dimensions and Anti-aliasing 
As you can see in the image on the left, below the render layer settings we have the dimensions and anti-aliasing settings.
The dimension settings are pretty simple: the X slider defines the width (in pixels) of your render, the Y slider defines the height (also in pixels) of your render. Above the X/Y sliders is a menu with some handy presets for commonly used resolutions, such as 1080p, 720p, and different TV resolutions. Below the X/Y sliders is another slider showing a percentage, the percentage indicates what size the render will be compared to the X/Y values. In the screenshot the slider is at 50%, so the scene will be rendered at half the size of the full resolution (in this case half the size of 1080p). This is a very easy way to quickly change the size of your render without worrying about numbers.
Now, let's move on to the render tab! The first thing you should notice is the VERY BIG button that says 'Render' on it. This button performs the same action as the F12 button. Below this is a drop-down box, allowing you to change between the Blender Internal Render engine and YAFRAY. (For more on YAFRAY, see YAFRAY Render Options). Next to the 'Render' button are 5 buttons: Shadow, Env Map, Pano, Ray, Radio. These are explained in detail below:
- Shadow: Lights will cast shadows. If this is turned off, nothing will cast a shadow. To see this, add a plane below your default cube and render. Now turn this button off and see how there are no shadows.
- EnvMap: Use the environment map.
- Pano: This enables panoramic rendering. For more on panoramic rendering, see Panorama Settings
- Ray: This enables Ray Tracing. Turn it off, and render the same images as I talked about in the description of the Shadow button. "What!?" you say. "That did the same thing as turning off the shadows! What's the deal?" Well, ray tracing is used to calculate how light goes through objects like glass and stuff. It also has something to do with shadows.
- Radio: This stands for Radiosity.
Moving on, the next button we come to is the 'OSA' button. For the use of this button, see OSA
To the right of the OSA button, are some percentages. These will set the renderer to render at the specified percent of the resolution that you have set. (We'll come to resolution later) For an experiment, press the '50%' button. As you can see, Blender renders the image at 50% of the set resolution. This is an easy way to make a quick render.
Next on our tour, we come to two boxes labeled 'Xparts' and 'Yparts'. These buttons change the number of boxes that Blender will render in total. Play around with these to see how they change the number of small boxes in the render window when you render.
Anim / Bake 
The final tab we'll (briefly) cover is the Anim(Animation) tab. If you have made an animation, pressing the 'ANIM' button will render your animation. Right below it are two buttons, Do Sequence and Do Composite. The Do Sequence button will render your animation with any effects you have done in the Sequence Editor and the Do Composite button will render an animation with your composite node work included. The Sta: and End: are the start and end frame numbers. The default setting is that your animation will start at frame 1, and will end at frame 250.