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The Materials (cmat files) Manual

Cafu materials are defined in material script files, which in turn are simple ASCII text files with file name suffix .cmat. This page describes how such “cmat scripts” can be written, their syntax and semantics.

Overview

First of all, here is a simple example for a material definition script. It was taken from the Cafu-9.06/Games/DeathMatch/Materials/Kai.cmat file, which also contains several other, very similar material definitions:

    Textures/Kai/3r_metpan01        // Material definitions start with the material name.
    {
        diffusemap  Textures/Kai/3r_metpan01_diff.png     // This line says which texture is used as diffuse-map.
        normalmap   Textures/Kai/3r_metpan01_norm.png
        specularmap Textures/Kai/3r_metpan01_spec.png
        lightmap    $lightmap
    }

Before we dig into the details about keywords and structure of such material definitions, here are some general properties of cmat files:

  • cmat files are simple ASCII text files, containing material definition scripts. Their file name ends with .cmat.
  • All statements in such files are case-sensitive. That means that text and Text are not the same. This is also true for filenames, like the Textures/Kai/3r_metpan01_diff.png filename above, because some operating systems like Linux have a case-sensitive file-system.
  • C++ style comments are allowed in material scripts: // This is a comment.
  • The cmat files for MOD “MyMOD” are all stored in the Cafu-9.06/Games/MyMOD/Materials/ directory and its subdirectories. This is necessary because the Cafu engine automatically scans this directory for material scripts whenever MOD “MyMOD” is run.
  • Tokens in cmat files are separated by white-space and these individual characters: ( { [ ] } ) ,
  • Quoted tokens are recognized. That is, everything between two "..." is considered as one statement, even if white-space or one of the above characters is inside it. That means, if for example you really want to have a material name like my(new and cool)material, then you have to enclose it in quotation marks like this: "my(new and cool)material" in order to account for both the white-space and the brackets. Using quotation marks is not recommended, though! They're mostly useful if somebody created textures with weird file names like for example "{_SomeFile.bmp". Write MyNewAndCoolMaterial or My/New/And/Cool/Material or something similar for your material names instead.

Material definitions always start with the material name. In the example above, that's Textures/Kai/3r_metpan01. You can name materials almost anything you like. If you want to use white-space, commas or brackets in their name, you'll have to put the name into quotation marks as mentioned above. However, it is important that the name is unique. If the same material name appears again in any other cmat file of the same MOD, the engine will use only the first occurance, so the chances are 50:50 that your material wins over the other. Most materials that come with Cafu have a filename that roughly resembles the name of its texture image files. That is often a helpful hint for conveniently working with the material, but by no means a requirement.

The body of the material definition is enclosed in a pair of { … }. In many cases, it will only contain a few texture map specification statements like in the example above.

matsys/cmat_manual.txt · Last modified: 2013-01-07 12:07 (external edit)