Updating material.cubemap doesn't update prefiltered textures

[daredevildave]

If a material has an existing prefiltered cubemap set, then updating the material's cubemap property material.cubeMap = cubemapAsset.resource will have no effect as this call doesn't update the prefiltered textures in the material.

Changing a material's cubemap should at least clear old cubemap data, and ideally update it to the new maps.