$decaltexture

$decaltexture is a material shader parameter available in Counter-Strike: Global Offensive. It allows for a second UV channel to be defined for a model, allowing a decal texture to be placed on top of the base material. To use the parameter, the MDL must have been compiled from an FBX file and have a second UV channel defined.

Bug:Using VBSP's -StaticPropCombine parameter appears to break this effect on autocombined models in some cases.  [todo tested in?]

Here, each label on the crates is laid out on a separate UV channel to that of the main texture – this allows easy and efficient reuse of the same labels/decals on many different props without losing texture resolution.

Parameters and Effects

$decaltexture <texture>

The decal texture.

$decalblendmode <integer>

Set the decal's blend mode.

• 0 - Alpha Masked
• 1 - Multiplied
  Note:If set to 1, $phong will not function on the material.
• 2 - Modulate (functions like DecalModulate, or Photoshop's Overlay blend mode)
  Note:Mode 2 expects sRGB input, not linear. This means ~0.73 gray acts as the mid point, instead of 0.5
• 3 - Additive
  Bug:Mode 0 and 1 will not render in Hammer, however the basetexture will still render. Mode 2 and 3 will cause the model to render completely black in Hammer. It will still render correctly in game though.  [todo tested in?]
  Note:$decalblendmode MUST be defined in order for $decaltexture to work.

$modeldecalignorez <boolean>

If enabled, model decals will ignore depth.