How would you emulate iridescent/pearlescent materials in PBR?
polycounter lvl 8
How would you emulate iridescent/pearlescent materials in PBR? Things like bug shells, soap bubbles, oil patches, etc. I've seen many ways people emulate the look using a non-PBR workflow- by using a saturated specular map or environment map. But since PBR works on the principle of light conservation, what would be the "correct" way to go about iridescence?
Replies
Soap bubbles, oil patches etc can be done with a Newton's ring shader. We have a Newton's rings specular model which can be added to the secondary reflection slot in Toolbag 2.
Check it out:
Now the real question, what is the reflectivity of soapy water?
Top: 4% reflective
Bottom: 15% reflective
Anddd with a detail normal map and displacement map it break it up a bit. IT would be cool to have some sort of oil map or something for the Newtons ring model but this is probably as close as I can get without custom shader work.
But yeah, iridescent/pearlescent are kind of their own thing and almost certainly would require a custom shader