$lightwarptexture
$lightwarptexture
(DX9+) is a material shader parameter available in all Source games since Source 2006 for VertexLitGeneric
, LightmappedGeneric
, WorldVertexTransition
, EyeRefract
. It tints texels depending on their brightness. It can be thought of as localized color correction.
Caveats
$lightwarptexture
must be specified after all other textures, otherwise it will overwrite them.
$lightwarptexture
on VertexLitGeneric
requires a $bumpmap
. If not specified, a default one will be used instead! It will be as if a $bumpmap
is in the VMT!
$bumpmap
also won't work with $lightwarptexture
.
- $detailblendmode 5-9 won't work - 5 & 6 will work when
$phong
is used. $envmapmask
won't work, except in Mapbase.$selfillum_envmapmask_alpha
doesn't work in any branch.
$phong
on VertexLitGeneric
in Counter-Strike: Source and CS:GO engine branch.$lightwarptexture
does not seem to exist at all for LightmappedGeneric
in CS:GO engine branch.$detail
or $bumpmap2
on both LightmappedGeneric
and WorldVertexTransition
.$phong
.$seamless_scale
.Lightwarp textures
A lightwarp texture is a one-dimensional strip of pixels. Dark texels will be tinted with the colour on the left-hand side, and bright texels with the colour on the right. 50% gray means no tint.
$lightwarptexture
on a brush or displacement will appear as if lightwarp were not present, whereas the same $lightwarptexture
on a model with no phong would result in the model being lit uniformly (like GoldSrc flatshade texture mode.VTF parameters
A lightwarp texture should use uncompressed BGR888 format to avoid undesired color banding on lighting gradients[1], and should be UV clamped.
If using VTEX, use these compile parameters:
nocompress 1 // disable texture compression, to prevent undesired color banding nomip 1 // disable mipmaps, which are unnecessary in this instance nolod 1 // always use the full resolution version of this texture (due to being low-resolution to begin with) clamps 1 // prevent tints at lighting extremes from blending together clampt 1 // optional? stripalphachannel 1 // remove unnecessary alpha channel, if present
Examples
ground/snow_warp.vtf
()- This is the lightwarp texture used in the Day of Defeat: Source screen above. It is designed to add a subtle bluish tint to darker snow without affecting brighter regions.
models/player/pyro/pyro_lightwarp.vtf
()- This is applied to all Team Fortress 2 characters, not just the Pyro. It creates the high-contrast shadows with red-tinged terminators typical of the illustrative art the game apes.
- Posterized (custom)
- This custom warp texture creates a posterized "line art" style. Enabling lightwarp alone isn't enough however: ambient lighting must be at 0 to make unlit areas black, and world lighting must become viewer-dependent to ensure that shadows are always cast.
- Cel Shading (custom)
- Cel shading can make objects look more cartoony by replacing the smooth lighting gradient with sharp steps.
Other possible uses of $lightwarptexture
include contrast enhancement, tweaking vertex lighting shadow transitions, highlight softening, and more.