Celestia/3D Models

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Introduction[edit]

In addition to its internally defined spherical objects, Celestia can use 3D models to display bodies with complicated shapes.

Usage in Celestia[edit]

A 3D model will be displayed when Celestia encounters the Mesh directive in one of its catalog files. For example,

Mesh "file.3ds"

If a Texture declaration is included in the entry for the same object, that texture image will replace all diffuse material texture images specified in the model file.

Model Types[edit]

Celestia can display three different types of 3D model files.

3DS[edit]

Originally developed by the authors of 3D Studio Max, the .3DS binary file format is used by many different software packages. Model files usually can be created in this format by choosing it in the "Export" menu of your favorite 3D modeling program.

CMS[edit]

CMS Model Files are unique to Celestia. They use a simple textual format. The CMS format is deprecated.

CMOD[edit]

CMOD Model Files are unique to Celestia. They have both binary and textual forms. The format was designed for efficient use by OpenGL code. When drawing a CMOD model, Celestia's framerate is about 1.5-2x as fast as when drawing the equivalent 3DS model.

A 3DS to CMOD conversion program is available. CMOD export scripts are available for Anim8or and Blender.

Modeling Programs[edit]

Modeling Hints[edit]

Limitations[edit]

  1. Models in Celestia do not (yet?) cast shadows on themselves or on other objects.
  2. Translucent model surfaces are not properly depth sorted. Some are drawn correctly, but some are not.
  3. DSC Nebula Meshes are not depth sorted at all. They always are drawn in the order that Celestia reads them.