Quick notes by LordHavoc (in need of cleanup and completion!):
All texture files are optional except for diffuse, a q3 shader allows additional options to be set but is not required for common materials.
textures/texturepackname/texturename.tga
Generally should have ambient occlusion baked into the color (in other words, the grooves are dark), but no shading.
textures/texturepackname/texturename_norm.tga
The normalmap is OpenGL-style with green pointing up (often normalmap tools call this “inverted”), matching Doom3/Quake4/etc behavior, but contrary to several other games.
The height channel is black for deep areas and white for being flush with the surface, the height is used only when offsetmapping (r_glsl_offsetmapping) or reliefmapping (r_glsl_offsetmapping_reliefmapping also on) are active.
For best results the height channel should be fairly smooth, no fine bumps, just the overall shape of the material.
textures/texturepackname/texturename_gloss.tga
The specular (gloss) color is full color and basically indicates how bright the specular reflection should when a light illuminates this surface, it should be black where you want the surface to look dull and bright where you want a shiny appearance.
For best results, color the gloss according to the material involved, for example plastic or car paint has a white specular color, copper has an orange specular color, gold has a yellow specular color, steel has a very slight blue tint to its otherwise white specular color, aluminum also has a very slight tint.
Generally the specular color should have ambient occlusion baked into the color (just like the diffuse does).
The alpha channel of this texture will multiply the specular exponent (r_shadow_glossexponent), white alpha will be sharp highlights, dark alpha produces very broad highlights very bright highlights, in general sharp highlights indicate metal or hard plastic materials, aluminum has a different specular hardness than steel, etc.
textures/texturepackname/texturename_glow.tga
This is the luminous glow of the material, pretty much you want this to be black with color only where a light emitting part of the surface exists (for example a series of red dots for red LED lights).
Be sure not to have any glow color in the diffuse texture as it will not add up properly.
Alpha is unused at this time.
texturename_reflect.tga – mask for the reflection, looks similar to gloss texture, basically this is where things will be shiny and what color of reflection (use orange for copper, yellow for gold, a slight blue tinted white color for steel, etc)
In shader: dpreflectcube map/mapname/reflect1
You can produce such a texture with this console command: envmap map/mapname/reflect1 512
Which will produce files such as:
map/mapname/reflect1px.tga map/mapname/reflect1py.tga map/mapname/reflect1pz.tga map/mapname/reflect1nx.tga map/mapname/reflect1ny.tga map/mapname/reflect1nz.tga
map/mapname/reflect1ft.tga map/mapname/reflect1rt.tga map/mapname/reflect1bk.tga map/mapname/reflect1lf.tga map/mapname/reflect1up.tga map/mapname/reflect1dn.tga
The first 6 are a cubemap, the last 6 are a skybox, keep one or the other set of files, you don’t need both.
In gamedir/scripts the engine will load all files with the extension .shader using a Quake3-compatible shader loader, however not all features will be utilized (for example it only supports one layer shaders, additional layers may be used to activate special behaviors – such as lightmapping – but will not be directly rendered).
The syntax of the Quake3-compatible .shader files is best explained by examples, so there are several here to look at.
Many additional features can be added to any shader with expected results, such as tcmod scroll 1 0 (makes a texture scroll in one direction), deformvertexes autosprite (makes a surface consisting of quads render as billboards facing the view), deformvertexes autosprite2 (makes a surface consisting of rectangular quads – not square – rotate around their long axis to face the view, useful for flame trail sprites and torch flames among other things)…
textures/texturepackname/texturename {
{ map $lightmap rgbGen identity tcGen lightmap } { map textures/texturepackname/texturename rgbGen identity blendFunc GL_DST_COLOR GL_ZERO }
}
textures/texturepackname/texturename {
surfaceparm noimpact surfaceparm nolightmap surfaceparm nomarks surfaceparm nonsolid surfaceparm nodlight surfaceparm trans { map textures/texturepackname/texturename blendfunc add rgbgen identity }
}
Note: you can omit some of the surfaceparms (keep trans!) when making a model material rather than a map material.
textures/texturepackname/texturename {
{ map textures/texturepackname/texturename rgbgen lightingDiffuse }
}
textures/texturepackname/texturename {
dpnoshadow { map textures/texturepackname/texturename rgbgen lightingDiffuse }
}
textures/common/shadowmesh {
dpshadow
}
textures/texturepackname/texturename {
dpreflectcube textures/texturepackname/reflect1 dpmeshcollisions { map $lightmap rgbGen identity tcGen lightmap } { map textures/texturepackname/texturename rgbGen identity blendFunc GL_DST_COLOR GL_ZERO }
}