Category is a logical grouping of any commands below it. This is mostly used to "inherit" rendering state. For example, your shader might have multiple subshaders, and each of them requires fog to be off, blending set to additive, etc. You can use Category for that:
Shader "example" {
Category {
Fog { Mode Off }
Blend One One
SubShader {
// ...
}
SubShader {
// ...
}
// ...
}
}
Category block only affects shader parsing, it's exactly the same as "pasting" any state set inside Category into all blocks below it. It does not affect shader execution speed at all.
Page last updated: 2009-07-24