From Valve Developer Community
Revision as of 18:52, 20 May 2011 by TomEdwards
In Source 2009 (
$ignorez (as in "ignore the Z axis") is a boolean setting that enables cheap sorting. Use it for interface materials, which will always be in front of the 3D world, and skybox materials, which will always be behind.
$ignorezcannot be used on models to prevent cheating.