I have rendered a hires image and now I see, it would be good to put a couple of Object IDs to a few objects.
Is there a way to render only a single multimatte render element with all the other elements deactivated ?
Perhapsis is there a script, which temporary turns all the other render elements off ?
In my scene i have a set of 20-25 render elements.
To accelerate the rendering of the MultiMatte I would switch GI, Lighting/Shadows, Glossy effects off.
But then the rgb would get dark or complete black.
Is there a way to force a edge antialiasing for that single MultiMatte render element, also then when the rgb is black ?
There is a script “Render Mask”, but I have some objects in my scene positioned behind glass planes and till now I do not have found a way to render the covered object using that script.
You could override everything with a black material and use fixed sampling, something like 5 to 8 subdivs should be enough to get you good AA (unless there is DOF and moblur in which case you might need more).
What I usually do in those cases is turning everything off as you said, but in Global Switches set Default Lights to ON, so there’s some shade for the adaptive AA to work. Vlado’s suggestion of using fixed sampler seems even better, though. Another trick is that when you check Override Material but let the slot empty, it uses the objects wirecolor, which might give a good variance for adaptive do it’s job. However I rather not to override materials since it will not work in case you have some MultiMatte using Material IDs.
This is the way I do it. Override with a black material, no reflection, then disable lights, shadows, textures, and turn off GI. Activate the multimatte element I need (or make a new one), and hit render. You’ll get a completely black frame that should render in a minute or so, and you’ll get your matte element.
