d3d_alphadepth, d3d_shadowdepth, d3d

d3d_alphadepth

d3d_shadowdepth

d3d_texdepth

d3d_skydepth

Defines the internal color depth (4, 16, 24, or 32 bit per pixel) of alpha channel TGA based textures (d3d_alphadepth), level shadow maps (d3d_shadowdepth), PCX/BMP based 16 bit textures (d3d_texdepth), or sky cubes (d3d_skydepth).

Range:

4 - 4 bit color depth (compressed).
16 - 16 bit color depth (default of d3d_texdepth).
24 - 24 bit color depth (default of d3d_shadowdepth and d3d_skydepth).
32 - 32 bit color depth (default of d3d_alphadepth).

Type:

var

Remarks:

Setting any color depth to 4 stores the textures in a compressed DXT format if supported by the 3D hardware. This can result in color artifacts and longer loading time due to the compression process. Compressed textures can not be accessed by pixel instructions.
DDS textures are already DXT compressed and thus do not require processing when loading.
24 bit PCX and BMP images are normally stored in 16 bit color depth, but can be stored in 24 bit by setting d3d_texdepth at 24.
24 bit TGA textures are always stored in 24 bit color depth ( except for sky cubes when d3d_skydepth is set at 4). They can be used for textures that require high image quality.
Setting a color depth variable before loading a level affects the textures and shadow maps of this level and its entities.

Example:

d3d_alphadepth = 16; // set all TGA alpha images to 16 bit mode
d3d_texdepth = 4;   // compress all except TGA based textures
d3d_texdepth = 24;  // render PCX and BMP images in 24 bit mode