Modulate

GIF Animation showing "Modulate" shader in action.

Modulate is a Pixel shader available in all Source games. It modulates the colors of any pixels behind it.

By default, it acts like the "multiply" layer mode in image editors, where full white (#FFFFFF) means no modulation, and darker values will darken what's underneath. If $mod2x is used, it acts like the "overlay" layer mode instead, where 50% grey (#7F7F7F or #808080) means no modulation, and lighter or darker values will lighten or darken what's underneath respectively.

A practical application of this shader is to create bloom-boosting textures, to create fake eye adaptation inside interiors. Other uses include faking various features that Source may not support, such as vertex coloring or lightmapping on models, by creating a surface above the first one to modulate it.

Description

Comparison of bloom boosting with $mod2x 1 + white basetexture and without

Picture showing the difference between $mod2x 0 and 1.

Accepts only the following parameters:

$basetexture <texture>

Modulates the color behind it with this surface's texture.

$mod2x <boolean>

Use DecalModulate blending instead of multiplication.

Code:Standard multiplication is equivalent to a BlendFunc of [DestinationColor,Zero], and Mod2x is equivalent to a BlendFunc of [DestinationColor, SourceColor]

$nocull <boolean>

Apply effect from through both sides of the polygon, instead of only through the front.

Note:Does not accept any translucency parameters, including $alpha, $alphatest, $additive and $translucent.

See also

• Refract
• Water