R20 Prorender SSS and reflections


I’m testing Prorender in R20, and I’ve realized that I can’t render subsurface scattering and reflections at the same time. I’m using a simple PBR material with a base color (Lambertian) and reflection (Beckmann) in the reflectance channels, with the SSS in the luminance channel. When the Luminance channel is activated, I can render SSS, but no reflections. When I deactivate the luminance channel, I can see the base color and reflections, but of course no SSS. The material renders as expected using the Physical and Standard renderers. Anyone else having this issue? I’m testing this on an iMac Pro with AMD Vega 64 GPU.


Works for me, though not with SSS at 100%. I think for it to be physically correct, SSS can’t be at 100% and have the reflectance on top; some lower fraction of SSS allows you to mix the reflectance and luminance to your need…


I’ll try your file here if it would help. Got a download for me? I’m on a regular iMac.

BTW - how are you liking ProRender so far? Worth pursuing with some eGPUs, or not?


NWoolridge is right; looks like I had the SSS strength at 100%. As far as my thoughts on Prorender, I’m still evaluating, but I’d say for me it graduated from “not ready for prime time” to “I can see using this on certain projects” in the R20 release. It’s decently fast on the Vega 64; I’d imagine it’s pretty impressive on a higher end eGPU setup, although I’m not sure the cost to benefit equation with eGPU’s is where I’d want it to be. I might try it on a real project soon as long as the project doesn’t have too many materials and I could quickly bail out to another renderer if things didn’t work out. It’s not going to put Octane, Redshift, etc. out of business, but it’s nice having a built in solution along these lines even if it’s not at the level of the best 3rd party renderers.


Thanks for the info. I’m right on the cusp of trying an eGPU in a last ditch effort to keep using a Mac for C4d. I was thinking of buying a Vega 64 which should work in conjunction with my internal RX580 to make it faster than Vega 64 alone, but perhaps it might be better spent moving to a PC.