I'm creating a scene that includes a thin piece of clear mylar with embedded circuit traces. I'm using a bump map to fake the relief of the traces. I've found two ways to make the edges of that bump map catch the light.:
1. Use Specular with an IOR above 1 to make the reflections visible. The problem with this is the more you crank up the IOR (to make the reflections brighter), the more refraction is applied to anything underneath the mylar. Thin pieces of plastic don't really refract what's under them, so this isn't a realistic approach.
2. Keep the Specular IOR at 1 but increase the Metalness to some value above 0. The bump texture will become brighter as the Metalness is cranked up. This seems closer to the realistic effect I want, but it's not very intuitive to crank up a function called "metalness" on a thin sheet of plastic.
In the built-in C4D shader system the reflectance and refraction are separate controls.
Can anyone offer any insight or suggestions about this workflow? I've attached a demo scene.
Marshall Arts Motion Graphics