SSS Pass compositing

[treyharrell]

I know this has been asked before, but there were bugs at the time regarding GI contribution, so I thought it might be a good idea to ask again.

I'm having issues matching my beauty renders right now when trying to use the SSS output of a FastSSS2 shader. Using it additively is *close* to the beauty, but not exact (the rest of the passes add up exactly).

Is there a certain trick to getting a 100% match?

Thanks,

--T

[griml0ck]

You can do "lighting + gi + refraction + reflection + specular - bea = SSS" in comp to get the SSS pass. The SSS pass you get from vray seem to have light baked into it.

[treyharrell]

Thanks, grim. For us it's not like the light's getting baked in (we're running a fairly new build) to our SSS pass... it's like we're off by 1-2% gamma. Getting the SSS by subtracting everything else out of the beauty will work for a 100% match, though... I just wish there was a better solution. It's just like skipping the rawlight passes (because they don't mult for 100% match... close, but not 100%) and just going for lighting.

Thanks,

--T

[gimiky]

are you using sub-pixel mapping? this might account for the difference..