Phong is a new rendering technique introduced to the Source Engine with Half-Life 2: Episode One. Phong looks best on a normal mapped model with some bit of specularity.
Phong supports two additional texture parameters
- Exponent Map -
$phongexponenttexture- Sort of gloss map where black is matte and white is glossy
- Occlusion Map -
$ambientocclusiontexture- Blocks phong from being applied in regions of the texture. The more black the less phong. (Or so I think)