$phong

Phong shading provides Alyx's skin, hairband and lip highlights.

$phong is a s2 available in all Source games since Source 2006. It is also available on the LightmappedGeneric and WorldVertexTransition shaders in all games since Counter-Strike: Global Offensive. It provides diffuse reflections at low intensity and specular highlights at apex intensity, masked by a texture which control per-texel its intensity. For a full explanation, see Phong materials.

Note:Phong shading for LightmappedGeneric and WorldVertexTransition is only available in

CS:GO engine branch. It requires the material to be lit by the sunlight from a env_cascade_light entity to work properly and uses the dynamic shadows generated by it as a mask on top of the traditional phong masking.

Note:Phong shading for LightmappedGeneric is also available in

Mapbase, but it is implemented differently.

Syntax

$phong <bool>

Note:All parameters in the following example must be specified in the material, otherwise Phong shading won't show up at all, except in

Insurgency.

Todo: Other games that don't require all phong parameters present (likely Portal 2 and up)

VertexLitGeneric
{
	$phong 1

	$bumpmap				[texture]
	$phongexponent			5			// either/or
	$phongexponenttexture	[texture]	// either/or
	$phongboost				1.0
	$phongfresnelranges		"[0 0.5 1]"
}

Parameters

Masking

Warning:There are some caveats regarding $normalmapalphaenvmapmask and $selfillumfresnel when using $phong!

Using $selfillumfresnel without $normalmapalphaenvmapmask will mask the $envmap using the $basetexture's alpha channel.
Using $selfillumfresnel with $normalmapalphaenvmapmask will multiply the $envmap by 0.0f. Effectively disabling the effect!
When not using $selfillumfresnel. The mask used for $envmap will be the $basetexture's alpha channel unless $normalmapalphaenvmapmask is also used.
If $normalmapalphaenvmapmask is used, the $bumpmap's alpha channel will be used for Phong masking. Using either $basemapalphaphongmask or $basemapluminancephongmask will override it.