Chaos Corona Forum
Chaos Corona for Cinema 4D => [C4D] I need help! => Topic started by: caspian on 2023-05-09, 00:45:43
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I've just completed a short render of a simple product of a plastic fume cupboard. For reasons I don't understand the frames were taking as long as 40 minutes each (res=1080p). Even the fastest frame was 15 mins. I thought maybe the caustics of the glass were responsible so I removed them. Luckily I didn't need my computer for three days! But now that it's rendered I'd like to understand if I did anything stupid to make it take so long to cook each frame. Just in case the client has any change requests… I appreciate that on Apple Silicone Corona is running in Rosetta so it's not as fast as it has the potential to be (right?) but even so I thought I'd have better performance.
https://www.dropbox.com/sh/09pog93tutjt42v/AAAxXjL5DSAIbtwKouQ43BuMa?dl=0
Mac M1, 12.6.3
Corona 9 Hotfix 1
C4D 2023.2.1
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Only had a very quick look - but didnt see any screamingly obvious errors.
There's a lot of plastics with sss though. I wonder if it''s all necessary? (it will take quite a while to clean up.)
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I also had a look. SSS will add to the render time depending on the frame (of course) I rendered 2 frames, one with glass and SSS and another without.
(https://forum.corona-renderer.com/index.php?action=dlattach;topic=39988.0;attach=182969;image)
(https://forum.corona-renderer.com/index.php?action=dlattach;topic=39988.0;attach=182971;image)
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I agree with the above, SSS always adds to the rendering time because it is quite a complex thing to calculate - regardless of the renderer you are using. So if possible toning that down could help you.
For animations what I sometimes do, and only in situations where I really just need the fastest possible output, I lower the MSI to 1. This will clamp the max ray intensity but it might reduce a lot of the noise you get from it. The downsides are somewhat obvious, your GI, your glass, your reflections and all that will be affected - hence why we don't really often recommend lowering this parameter.
Still, even if the glass will look dimmer and you'll loose out on some of the "realism" that you get by not clamping things that much it might be totally ok for the scene you're working on here - and it might help lower those render times.
Other things would be trying to fool around with the GI vs AA balance + lights sample multiplier.
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I'll remove the SSS on all but the rubber elements next time round.
What do you mean by 'lower the MSI to 1'? Where is this?
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I'll remove the SSS on all but the rubber elements next time round.
What do you mean by 'lower the MSI to 1'? Where is this?
MSI = Max Sample Intensity, sorry for not being clearer with my earlier message.
You can find it in the Corona render settings -> Performance Settings under the Speed / Accuracy Balance compartment.
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Thanks for your help. Things are speeding up.
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My 2 cents:
1 - As far as I understand from the screenshots, you are using noise limit as the condition to stop your rendering. Try using pass limit or time limit. This way you will have better control over render time per frame, and it might turn out that the noise limit was resulting in an overkill (rendering more passes than needed to reach reasonable quality).
2 - In addition to the above, you can enable denoising. This way, you can render to an even lower base quality and still get acceptable results.
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I always use denoising. But I will look at specifying passes instead as there are some frames in the middle of the animation that take double the time, which is probably to do with my noise specification.
Thanks for the tip.