I couldn't find a previous discussion on this around the forum, Mantra does strange things with its reflections on certain angles. This is something we had as well back when we first started using Arnold back in the day, but got resolved by the developers.
In essence, there are quite a few cases in almost all our shots where the reflection would suddenly ping to super whites “3+” on certain angles, in most cases on the rim lights . I know Mantra uses IOR to determine the front/back reflection. Is there a way to get more control on how to manage this without sacrificing the integrity of the lighting? Even if we clamp the samples to 1, there will still be pings of pure white on certain angles even though my reflections are turned way down. Is it something to do with the IOR setting or is it a sampling issue? This happens on both the Mantra surface and Principle shader.
Managing Reflections
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- Christophe Leyder2
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- Enivob
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- Christophe Leyder2
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I unfortunately cant post anything from this project for obvious contractual reasons. But what we are doing involves large crowds and feathers. (its pretty easy to replicate this problem I can make an example when I find the time).
In both cases in almost all the shots we get intense pings and fireflies, the fireflies in particular took some figuring out to get rid of. Tried bringing the color limit down to 1 from 10 and nothing happens (weirdly enough, even though it was limited to 1, I was still getting pixels that were super whites 3+). I put the pixel sampling 12+ and nothing changed. The only way I managed to get rid of the fireflies was to get rid of all reflection bounces entirely, and that seems to have solved it, luckily in this case it hasn't affected the look of the shots too much.
Does scene scale also have some sort of an effect on it? I had a very large area light in the scene, when I made it smaller some of them disappeared.
Strangely though, it seems to affect shaders that are on deformed objects more than not, I'm not sure why.
So essentially, fireflies have been temporarily sorted out, but the intense pings still remain.
In both cases in almost all the shots we get intense pings and fireflies, the fireflies in particular took some figuring out to get rid of. Tried bringing the color limit down to 1 from 10 and nothing happens (weirdly enough, even though it was limited to 1, I was still getting pixels that were super whites 3+). I put the pixel sampling 12+ and nothing changed. The only way I managed to get rid of the fireflies was to get rid of all reflection bounces entirely, and that seems to have solved it, luckily in this case it hasn't affected the look of the shots too much.
Does scene scale also have some sort of an effect on it? I had a very large area light in the scene, when I made it smaller some of them disappeared.
Strangely though, it seems to affect shaders that are on deformed objects more than not, I'm not sure why.
So essentially, fireflies have been temporarily sorted out, but the intense pings still remain.
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