https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_materials_dispersion https://github.com/KhronosGroup/glTF/pull/2340 <img width="764" alt="Screenshot 2024-03-07 at 10 52 17" src="https://github.com/playcanvas/engine/assets/59932779/46604319-0544-4c23-a49b-ab8e301bc81e">  test model: https://github.com/cx20/gltf-test/tree/master/tutorialModels/DispersionTest
