Texture Color Map

Recolors the Base texture by looking each pixel value up in the Map gradient.

The Map is read along its top row only (its height is ignored), so it acts as a left-to-right gradient: position 0.0 (left) corresponds to a value of 0, and position 1.0 (right) to a value of 1. Each value of the Base is used as the horizontal coordinate into this gradient and replaced by the color sampled there — so dark values take colors from the left of the Map, mid-tones from the middle, and bright values from the right.

The mapping is applied per channel: the Base's red is mapped through the Map's red, green through green, blue through blue, and alpha through alpha.

The optional Mask (a grayscale texture) restricts the effect: only pixels where the mask is above ~0.5 are recolored; the rest are kept unchanged.