Consider accepting arbitrary shader materials api

[Nathan Pointer]

Would be cool if you could provide arbitrary material shaders to be associated with each splat channel instead of predefined textures.

[Nathan Pointer]

<mesh position={[0, 0, 0]} rotation={[-Math.PI / 2, 0, 0]}>
      <planeBufferGeometry args={[100, 100, width, height]} />
      <SplatStandardMaterial
        splats={[splat1, splat2]}
        materials={[grassMaterial, rockMaterial,...]}
        scale={[128 / 4, 128 / 2, 128, 128 * 2, 128, 128, 10]}
        noise={noise}
        displacementMap={displacement}
        displacementScale={10}
        displacementBias={-10}
      />
    </mesh>

[Nathan Pointer]

will not be making it into the next major version so closing for now