Lut, Shader, Programming, Blender3d, Unreal Engine.
multiplaying our InColor.B by 4, we will get a number between 0 and 1, flooring it we will get 0 again. Which means everything between 0 and 0.25 will get an offset of 0, between 0.25 and 0.5, offset of 1, between 0.5 and 0.75, 2 and between 0.75 and 1 it will be an offset of 3. Of course we want