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The "infinitesimal gap" method was the only way to ensure every ray enters and exits the mediums in the correct order
Nested dielectrics
NEW IN MAXWELL V3.2
The best way to overcome this situation is by using the nested dielectics approach. Using this approach, two dielectric bodies can overlap and the render engine can automatically "boolean" them in render time and remove the surplus volume leaving just one single polygon wall, and assign the proper material for that single wall depending on the direction of the incident ray.
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