Thin Dielectric Sheets
A thin dielectric sheet can be applied to the one side of a face to model flat multilayer dielectric structures. Typical applications include radome covered antennas and windscreens of automobiles.
For example, a model is simulated with two layers. One layer is a good absorber and the second, a good conducting layer. When a ray is incident on the side of the absorber, the reflection is zero. When a ray is incident on the side of the conducting layer, the reflection coefficient is -1. The transmission factor in both cases is zero.
The definition of which side is the front / rear is determined by the normal vector n of the triangles. If one ray is incident in the direction of the normal vector (ray 1) and as a result hits the first layer (index number n - layer with the highest index number). An incident ray in the opposite direction of the normal vector (ray 2) will first hit the layer with the lowest index number.