View source for Texture shadows

[[File:Textureshadows portal2.jpg|thumb|right|Texture shadows in Portal 2]]

Texture shadows allow transparent [[model]] surfaces (not brushes or displacements!) to cast baked lightmap shadows.

To enable model texture shadows, add {{code|-TextureShadows}} to the [[VRAD]] parameters.

{{only|{{slammin}}}} To enable brush and displacement texture shadows, add {{code|-worldtextureshadows}} (and optionally {{code|-translucentshadows}} for translucent shadows) to the [[VRAD]] parameters.

{{modernImportant|Only the alpha channels of the textures are used for shadow casting calculations. For example, stained glass windows using the {{ent|Refract}} shader will be treated as opaque.}}
{{bug|VRAD is unable to calculate texture shadows for textures using DXT3 compression. Use DXT5 instead.|tested={{hl2dm}}}}

== Models ==

=== In QC ===
Add {{ent|$casttextureshadows}} to the model's QC file to enable texture shadows.

Example:
<pre>
$modelname "props_grate/metal_grate_64.mdl"
$model body "metal_grate_64.smd"
$staticprop

$cdmaterials "metal/"

$surfaceprop "metal"
$contents "grate"

$casttextureshadows
</pre>

=== lights.rad ===
Texture shadows can be enabled on any prop without editing and recompiling the QC through the [[RAD file]].

Example
<pre>
forcetextureshadow props_underground/walkway_128a.mdl
forcetextureshadow props_underground/walkway_128b.mdl
</pre>