Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: romullus on 2013-12-30, 19:40:14
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While working on some personal project, i encounter strange behaviour of hd cache, which i cannot resolve on my own. Its strange blobs of light. Each time it appears in different places and it doesn't goes awway with bigger amount of passes. I tried many things with little success. The only thing that helps somehow is lowering precomp steps of hd cache to 0,1 but whole image becomes grainy.
Ofcourse, i could render image with pt+pt and forget it, but i'd like to understand what causes such behaviour. Btw, i don't know if it's related to this problem, but hd success rate is unusually low in this scene - 50-60.
Attached gifs is not animation, its one frame rendered 10 times in a row.
edit: animated gifs seems not working here. Where i could upload them?
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it looks like the cache cannot deal with this complicated scene (the enclosed environment with all walls glossy make it pretty hard). What is your settings for:
- HD cache PT samples (in hd cache rollout)? Try increasing it
- max sample intensity (main rollout)? Try decreasing it
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Stunning render quality.
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Hi Keymaster, thank you for your help. I already tried to tweak your suggested values with little success, but i'll give it another try for sure.
One thought, could it be because of my unusual setup for lighting fixture? Maybe i should try geometry with emmiter material instead?
edit: i should mention that scene was initially created for mental ray. I converted material with converter (thanks DeadClown for this wonderfull tool!). But afterward i tweaked every material by one o be sure that there's no exessive albedo.
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Sorry for the offtop but... spherical lens? How?
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Thanks to Keymaster problem solved. Actually both suggestions worked well, but i didn't liked how low msi killed those secondary reflections. So i'll stick to higher hd cache pt samples. And hd success rate now is a lot better - over 70. Where i could find a little bit info about hd success rate? I tried forum search, but no luck.
maru, it's a little trick, that i learned while worked with mental ray. Its a sphere in scene with super mirror material with unchecked cast shadow, visible to reflection, etc. And camera is pointed to that sphere. That way you get perfect fisheye lens :]
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hd success rate is the rate at which is HD cache accelerating the calculation - more means more points get interpolated from the cache. But 100% cannot be obtained. 70% is still a solid result in such glossy scene
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or
set position sensitivity to 60 or more.
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maru, it's a little trick, that i learned while worked with mental ray. Its a sphere in scene with super mirror material with unchecked cast shadow, visible to reflection, etc. And camera is pointed to that sphere. That way you get perfect fisheye lens :]
Crazy! But I think it could still affect rendering, especially in Corona if you unchecked cast shadow and reflection visibility in object's settings.
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Polymax>> i'll try your suggestion as well, thanks!
maru>> i'm sure it affects render in some way, but i like FE effect so much, i can't help myself :] I hope Keymaster will implement spherical projection camera someday.
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Rising position sensitivity helped great deal and it didn't add to render time. I wonder what is drawback of that solution?