I have an object, glass bulb that has it's top covered with mirror like material on one side, dull material on the other side. So technically three materials, but I cheated with Corona Front Back map for mirror/dull one, and used just a regular glass one for the other. Mix them with gradient map in Corona layered material. They have to gradually transition from glass to mirror.
Turns out this layered material slows the render down, a lot. In my scene expected render time 30+ hours. With just the glass material assigned, or just the mirror one, it's about 12 hours. Usually render times on my PC end up being double of what is predicted after 5-10 passes, so 50-60 hours for a single image is a little too much.
Path tracing or UHD cache, the same.
Turning on "Thin (no refraction)", didn't help.
Turning off Shell modifier on the geometry helps a bit, but negligible.
Turning on Caustics helps a bit, but negligible.
Switching base material and layer 1, didn't help.
Test scene with the material attached.
Can anything be done to speed it up? Thanks in advance!
