// If we have a lit shader, only the UV0 is available for opacity or heightmap
// If we have a layered shader, any UV can be use for this. To reduce the number of variant we groupt UV0/UV1 and UV2/UV3 instead of having variant for UV0/UV1/UV2/UV3
// If we have a lit shader, only the UV0 is available for opacity or heightmap
// If we have a layered shader, any UV can be use for this. To reduce the number of variant we groupt UV0/UV1 and UV2/UV3 instead of having variant for UV0/UV1/UV2/UV3
// If we have a lit shader, only the UV0 is available for opacity or heightmap
// If we have a layered shader, any UV can be use for this. To reduce the number of variant we groupt UV0/UV1 and UV2/UV3 instead of having variant for UV0/UV1/UV2/UV3