Maya 2018 - How to remove specular artifacts with Nuke 10 Studio?

#1

I´m getting too much specular small artifacts in some parts of my scenes and i´m kind of tired of Arnold and redoing those parts… its a long rendering process and i have to continiously go back and redo multi part in scenes and each time i increase the speculars at Arnold render settings it takes like 7 minutes more for rendering each frame making this process an infinite lose of time, days of rendering by using render sequences; so i just want to fix this small litle artifacts that suddenly appear at my scenes involving specular by fixing them in post with Nuke 10 Studio, how can i do this? it can´t be just a denoise because its like lots of small white points on dark scenes…dont know how to fix that, and haven´t find a tutorial yet.

Any idea, please help

#2

Can you show us an image? Do you talk about fireflies? If yes, you can eliminate a lot of them by setting a clamp value in Arnold which limits the maximum value a sample can get. It shuould work in Nuke as well if you rendered to an exr sequence. Try a clamp node or a softclip (not sure about the exact name).

#3

First time i heard that term for maya… .i was introduced to artifacts with Arnold, never had this problems before, it looks like in the scene suddenly over any object with specular, small white dots appear, those dots appear really fast and dissapear and it happens over several frames like little white shines, it looks like if those objects had little diamantine over and they suddenly shine… .its awefull and i already made my specular and AA settings so high for Arnold… that it takes me about 30 minutes per frame and every scene involving specular even if its just a few seconds scene takes me days to render because of those white dots that i can only make dissapear if my values are ultra high… i do have seen somme clamp options on Arnold settings, but dont know how it works or if this is what solves my white dots issues over specular.

#4

yes the clamping will remove those white spots called fireflies…
https://support.solidangle.com/display/A5AFMUG/Fireflies+-+Boat+Scene

#5

It worked as a charm,

Arnold guide wasn´t specific about how to do it, this is what you have to do: In Arnold Renderer option you have to select “Clamping”, check “Clamp AA Samples” and also lower “Indirect clamp value” to 1 or less, for me it worked at 0.7

Thanks a lot!

#6

Just a small hint in case anyone is working with Cryptomatte: Cryptomatte does not work with clamping because it needs full 32bit float values.