$ssbump

$ssbump is a material parameter that flags a $bumpmap as being self-shadowing. It is only supported with LightmappedGeneric and requires the Orange Box.

You can read more about the technology behind it in this paper.

Tip:Self-shadowed normal mapping is actually faster than the standard method!

Example

rockwall_cave_02a_height-ssbump.vtf

LightmappedGeneric
{
	$basetexture nature/rockwall_cave02a
	$surfaceprop concrete
	$bumpmap nature/rockwall_cave_02a_height-ssbump
	$ssbump 1
}

Creating self-shadowing bump maps

Valve's tools for creating ssbumps aren't in the SDK yet, but there is a way to create them manually.