I am selecting textures from the texture array based on the indices stored in the meshes UV. But I would like to have 3 colours for the texture that would be chosen for each of the terrain array indices.
bumping
I’m not entirely sure what you’re asking for.
You want 3 unique color values per texture index? You want another texture then. Something like a 2D atlas of 3xNumLayers that you sample from, or a 3x1 texture array, or even 3 1x1 texture arrays if you want to make it a little simpler in the shader.
Alternatively you could use a vector array, but Shader Graph doesn’t support array uniforms, so you’d have to use a Custom Function node with a separate .hlsl file that lists them out and accesses them.