Texture shadows
Texture shadows allow transparent model surfaces (not brushes or displacements!) to cast baked lightmap shadows.
To enable model texture shadows, add -TextureShadows to the VRAD parameters.
(only in 
) To enable brush and displacement texture shadows, add -worldtextureshadows (and optionally -translucentshadows for translucent shadows) to the VRAD parameters.
Important:Only the alpha channels of the textures are used for shadow casting calculations. For example, stained glass windows using the Refract shader will be treated as opaque.
Bug:VRAD is unable to calculate texture shadows for textures using DXT3 compression. Use DXT5 instead. (tested in: 
)Models
In QC
Add $casttextureshadows to the model's QC file to enable texture shadows.
Example:
$modelname "props_grate/metal_grate_64.mdl" $model body "metal_grate_64.smd" $staticprop $cdmaterials "metal/" $surfaceprop "metal" $contents "grate" $casttextureshadows
lights.rad
Texture shadows can be enabled on any prop without editing and recompiling the QC through the RAD file.
Example
forcetextureshadow props_underground/walkway_128a.mdl forcetextureshadow props_underground/walkway_128b.mdl
