$phong

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

The $phong VMT command provides diffuse reflections. For a full explanation, see Phong materials.

Note:Phong shading is only available with VertexLitGeneric.

VMT syntax

$phong <bool>

The Phong shader should use the default values for any configuration parameters that you omit from your material. However it appears that this doesn't happen. Therefore all of the below parameters are required, even if they stay on their default values.

VertexLitGeneric
{
	$phong			1

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

Additional parameters

$bumpmap <texture>

See $bumpmap. Its alpha channel acts as a Phong mask.

$phongexponent <int>

$phongexponenttexture <texture>

See Phong mask and exponent texture. The texture value is overridden by the numeric value (if the latter is present).

$phongboost <int>

Phong overbrightening factor. The phong mask channel should be authored to account for this.

$phongfresnelranges <matrix>

See Phong Fresnel ranges. Default is "[0 0.5 1]".

$phongwarptexture <texture>

Used to create an iridescence effect on npc_hunters.

Todo: Needs documentation.

$lightwarptexture <texture>

See $lightwarptexture. A 1-dimensional ramp texture that tints depending on brightness.

$phongalbedotint <?>

Allow the albedo (i.e. $basetexture) to affect the colour tint of the Phong highlight? Possibly related to the green channel of the Phong exponent mask. Seen in some Day of Defeat: Source player model VMTs.

Todo: Needs documentation.

$ambientocclusiontexture <texture>

A "dirtmap". Mentioned in the SDK samples and seen in the VMT for Alyx's face.

Todo: Needs documentation.

$basemapalphaphongmask <1/0>

Enabled this if the phong texture is in the basetexture's alpha mask.

"GPU>=2?$phong" 1

(Use with $phong 0) Only uses phong if the current PC is using dual GPUs.

Todo: Check if correct, it may be wrong

See also

• Phong materials
• $basetexture
• $envmapmask (specular mask)
• $envmap (environment map)
• $selfillum