Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: pscgi on 2022-10-19, 23:45:44

Title: Does the background color matter for the rendering times
Post by: pscgi on 2022-10-19, 23:45:44

Hi. I'm rendering an animation scene full of trees right now and at first I forgot to set the background to black to get rid of those nasty edges after adding background video in post production and looks like after making that one change, the rendering time is now much much better. With white background and with my 5950X it took 40 minutes to reach 15% noise level and after changing the background into black I reached 10% after 38 minutes so were those indeed those trees edges against the white background that were causing a lot of noise?

Title: Re: Does the background color matter for the rendering times
Post by: maru on 2022-10-20, 09:37:15

The real question is: if you use time limit instead of noise limit (e.g. set time limit to 30 minutes) will the image with black background really have better quality than the one with white background?

What I think happened here is that the "white background" image had some visible sky details in it (like an HDRI or Corona Sky) and this caused two things: there was more sampling required than in the case of black background, and the detail might have affected the reported noise level. But these are just speculations and it would be nice to at least see what we are talking about. :)