Layered Material

A layered material allows you to stack multiple materials on top of each other. Unlike the multipass material, the order of traversal is determined by the normal of the geometry. This allows it to use the layered material as a two-sided material.

Additionally, glass materials are handled in a special way. If two glass materials are added to the layered material the index of refraction of these glass materials are adjusted in a way that allows to use them in glass-on-glass contact situations. If you add more than two glass materials, only the index of refraction of the first and last glass material is considered, all other glass materials get an Index of Refraction of 1.0 and act as a color filter if material density is turned off.

Changing the drawing order of layers could be done within the material editor from standard UI.