Author Topic: Extremely Slow render times  (Read 9152 times)

2021-12-31, 09:17:34
Reply #15

3DInteriors

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Hello ! Can you send me the scene file ? I Have got Threadripper 3970x ( 32core ) with 64GB Ram.

2021-12-31, 10:44:38
Reply #16

Armand Rudy

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A low-quality HDR can produce bad shadows and noise. Also, if your system is running out of RAM it will swap with the hard drive which is dramatically slower unless you have super fast SSD. Also consider the resolution of your materials. In my opinion, only the trees near the camera could use such high resolution textures. It's just overkill unless you are rendering different shots in the scene then that makes sense. C4D loads all of those 4k and 6k images into RAM. I don't know the sizes you have, but I can imaging each of them could be hundreds of MB or more for each one. That CPU is not world-shattering speed-wise. I see online it's does 12195 in the Cinebench r23 multi-core test. For example, my 5-year old iMac Pro comes in around 16737 in multi-core. Either one is nothing compared to Threadripper 64, but then again, that $4,000 USD just for the CPU. I get it.

What I love about Corona is you can still get decent speed on older CPUs. I think it's a matter of learning to adjust your scene for best optimization.

Do a quick test. Change your sky to Physical Sky (no HDR). Maybe add a Sun to match your shadows. Set your settings to match mine to override all materials and render a test. Try 100 passes or use the Noise Level Limit to 5 and hit render. See if you still have noise. If you do NOT, then I suspect it's the HDR creating the noise.

Sorry, I'm rambling a bit. Post back your results. Good luck.

Another thought. If it really is such a small area giving you trouble, consider rendering just that area with more passes, then just paste them together.

I managed to cut down the render times from 10 to 4hours using only corona sky+sun

I decided to redo all the texturing, 4 hours is still too long for me, I have to deliver like 8 renders interior included...
I will also look to replace all the trees.

Thanks for the help, you guys are awesome.


2021-12-31, 10:45:34
Reply #17

Armand Rudy

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Hello ! Can you send me the scene file ? I Have got Threadripper 3970x ( 32core ) with 64GB Ram.

What is the best way to send a 1gb compressesd file?

2021-12-31, 11:20:10
Reply #18

romullus

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I decided to redo all the texturing, 4 hours is still too long for me, I have to deliver like 8 renders interior included...
I will also look to replace all the trees.

Just a word of caution, if the scene is fitting into RAM (even if Corona shows warning about low RAM), then making textures smaller, will not make any difference in render speed. It only makes sense to reduce textures, when your scene does not fit into RAM and start using swap file, but in that case we're talking not about difference between 10 vs 4 hours, but rather 10 vs 1000 hours.
I'm not Corona Team member. Everything i say, is my personal opinion only.
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2021-12-31, 15:41:58
Reply #19

3DInteriors

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2022-01-04, 14:21:06
Reply #20

rojharris

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Just to add; I've been using Corona for years and I don't think I've ever used more than 15 passes with the advanced denoiser set to 0.5 or 0.65.. Never had an issue with noise. Remember that some noise can actually help your scene look more realistic. Like film grain from a camera. There's no law says you have to eliminate all of it.

2022-01-08, 00:20:39
Reply #21

ficdogg

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With render farms being so cheap,a year or two ago I stopped rendering stuff at home.
Anything that takes longer than 30min I simply send to Rebus and continue working on other stuff.
Even if you have a threadripper at home, it cant match 5, 10 or 20 threadrippers rendering at the same time.

2022-01-12, 18:28:38
Reply #22

Matthew86

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With render farms being so cheap,a year or two ago I stopped rendering stuff at home.
Anything that takes longer than 30min I simply send to Rebus and continue working on other stuff.
Even if you have a threadripper at home, it cant match 5, 10 or 20 threadrippers rendering at the same time.
Do you pay for every test render with Rebus? Or is a sort of subscription?