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Switch to custom shaders - a custom vertex format feeds in diffuse and lightmap texture coordinates.
Lightmap textures only.
Result = Lightmap * Diffuse
Simulation of software Quake 2 by using greyscale lightmaps.
Pixel shader used to ripple the texture.
A pixel shader can be used to convert a palette index and brightness into a colour via a colour map texture.
The 8-bit look mimics software Quake.