Arnold/Vray GPU vs CPU rendering quality

OccultMonk

Can you get the same results with GPU rendering as CPU? I know there are some limitations for GPU renders. But if you compare the results of Corona/Vray/Arnold CPU renderers with Arnold/Vray GPU versions do they result in loss of quality compared to CPU? And why would you choose CPU over GPU renders, except maybe for very large scenes?

oglu

There is no quality loss. You have to use higher sample settings. The GPU sampler does work different. In case of Arnold its the exact same render engine. 

OccultMonk

Then why would you still use CPU except for scenes with very dense geometry?

oglu

Volumes like VDB or unique displaced geometry does fast fill the GPU ram. But if your scene does fit into the ram there is no reason to use the CPU.

Maybe if you need a special feature that is not supported in GPU ? Just check the comparison charts.

Next month Renderman should be available with a GPU version. This could be interesting. 

https://docs.arnoldrenderer.com/plugins/servlet/mobile?contentId=86805372#content/view/86805372


https://docs.chaosgroup.com/m/mobile.action#page/60895937

OccultMonk

Thanks!

TeZzy

I can't speak for the other renderers but from what I have experienced, Arnold's GPU rendering has some limitations. So far I have found that in GPU mode, if you want an object to act as a matte/black hole (doing it via the shape attribute or in the shader), it will not work. But works as you would expect in CPU mode.

@oglu -  Is that something you can confirm? 

oglu

Thats true. Matte shader arnt working in Arnold GPU like you can see in the link above. But im sure they add it in the future. 

Have in mind that Arnold GPU isnt that long in development. If you need a full featured GPU renderer go with Redshift. 

TeZzy

Thanks for confirming oglu. Yeah, Redshift is my go to when I have a choice.