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Rendering with Arnold in CINEMA 4D using the C4DtoA plug-in.
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Thin Walled SSS Geometry is destroying mattes

Message 1 of 9
668 Views, 8 Replies

Thin Walled SSS Geometry is destroying mattes

Hi Guys,

I need masks for a project right now and I've come to the conclusion that Objects with Thin Walled SSS are receiving illumination from the mattes and/or are computing the subsurface effects, so the masks are unusable.

Once I turn thin walled off everything works as expected.

I've attached a screenshot showing how a matte looks with thin walled sss geometry in it.


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Message 2 of 9

Can you send me a scene or some screenshots of the shader parameters?

Message 3 of 9
in reply to: infoMMJ2X

Hi Peter,

I've attached a scenefile for you - I don't believe this is intentional behaviour. If it is, I think it would be nice to have something like a "Transmit AOV" checkbox for SSS. But as the standard SSS isn't showing this effect I think it might be a bug.

Thanks for looking into it!

Message 4 of 9

Could you please post me a screenshot of the issue in the shared scene? Only the camera rays are written to a custom AOV, no indirect, so it should look fine and I don't see any problems in your Multimatte AOV. Looks the same with or without Thin Walled enabled. Maybe I just overlook something.

Message 5 of 9
in reply to: infoMMJ2X

Message 6 of 9

That's weird, this is what I've got in the IPR:


What's your C4DtoA version? Win or OSX?

Message 7 of 9
in reply to: infoMMJ2X

I'm on still, on C4D R18 and Win7 64bit.

Message 8 of 9

OK, I've got it. It looks correct in the IPR, but not in the Picture Viewer. Which is odd. Seems like a bug, and reminds me of an issue with the object masks reported earlier. I'll take a look.

Message 9 of 9

Supposed to be fixed in C4DtoA 2.3.1 (Arnold core

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