Chaos Corona Forum
Chaos Corona for Cinema 4D => [C4D] I need help! => Topic started by: laurack on 2025-01-10, 11:14:18
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Hi, again when rendering a video the fireflies appear despite having the configuration that I used in another video and that they were removed there.
I'm going crazy because if I use Corona's interactive rendering mode the image appears clean and perfect but when I launch the "Star production rendering" the frames appear with a lot of noise and the damn fireflies.
I have tried configuration variations but I can't get rid of them. I put a screenshot with what happens and how I have the parameters configured.
Thank you very much.
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Howdy! To me it looks like you have one of the AI denoisers enabled when doing Interactive Rendering whereas the final renders are without any denoising.
So if you want to have a matching image to the IR one you ought to enable the same denoiser for your final renders as well.
Or let it render longer :)
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Hi Nejc.
I have interactive rendering set by default, I don't know where it is indicated or how it is activated in the final rendering?
I also tried the option to give more render passes but it doesn't solve the fireflies.
Thanks!! ^_^
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Our tutorial on Denoising is at
and should answer any questions you have :)
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I saw it not long ago, I'm going to look at it again to see if I can understand it better with my terrible English >_<
Thanks!!!
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In case it helps, as reading can be easier (and open to things like Google Translate, plus the UI grabs are static so you don't have to race to keep up), there's also the article on the help documentation at https://support.chaos.com/hc/en-us/articles/4528591107729-How-to-use-denoising-in-Corona-for-Cinema-4D . Let us know if you end up with any questions!
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Also, get to know "Highlight clamping" (https://forum.corona-renderer.com/index.php?topic=35000.msg192333#msg192333).
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Thank you all very much, I finally managed to remove the fireflies in the render. ^_^
Regards¡¡¡
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Great news! And you are welcome, that's what the community is here for :)
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Argggg, I'm going crazy!!
I'm uploading some screenshots with what's happening to me with the fireflies.
I need the video to have bloom and glare to be able to generate the reflections of the sun and light but if I set the Highlight clamping value to 0 it generates the dreaded fireflies, but if I set the value to 0.5 they disappear but the glare and reflections are also eliminated.
I've tried with different Highlight clamping values between 0.1 and 0.4 and as you can see in the third image the results are disastrous.
I want to remove the fireflies but without losing the glare and reflections, what am I doing wrong?? :-(
Thanks.
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I'd suggest lowering the MSI (Max Sample Intensity) to a lower value - 1 or 2. That could help as well :)
It does sound like you're doing something funky somewhere in your workflow because generally the fireflies should be minor and even then they should be cleaned up rather nicely by any of the denoisers.
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The thing about "Highlight clamping" is that it clamps light contribution all over. So other parameters need to be balanced accordingly. It ain't magical solution. Tho, from looks of it I suspect you got issues elsewhere... HDRI, highly reflective surfaces, caustics,... unreal values?
couple of tips:
- Keep it as close to physically accurate as possible.
- Learn about 'Light painting' and 'multi-exposure' techniques commonly used in photography.
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Thanks, I've only been rendering with camera movement for a relatively short time and it's clear that I'm doing something wrong. We also have a photography studio and I'm pretty good at it, but putting this knowledge into Corona with so many parameters drives me a little crazy >_<
I'm analyzing what you're telling me to see if I can solve it, although the vehicle's chrome and paint materials are the ones that come by default in Cosmos Browser.
Regards.
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Hi, I'm uploading the rendered video where you can see how the fireflies continue to appear :-(
I'm also uploading the configuration I used, making variations based on what you've previously advised me, but as much as I've tried, I haven't been able to eliminate the fireflies.
What am I doing wrong?
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This type of fireflies is expected since a very small light source (sun) reflects/refracts in various materials. I would advise either:
- adjusting the lighting (e.g. making the sun disk larger or "softer" - blurring it a bit)
or
- using a 3rd party denoiser or firefly removal tool
These fireflies will be mostly visible if you are rendering your frames for a very short time. What is your render time per frame? What kind of limit are you using? You probably need to render at least 50 passes per frame, definitely not less.
Lastly, please revert you performance render settings to defaults - GI/AA balance to 16, light samples multiplier to 2. With Corona, you should generally use the default render settings. Usually there is no need to change them.
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Thank you very much, I will try what you mentioned about the sun disk, which is probably where the problem comes from :-)
I have made the render with 50 passes for each frame and it has taken about 50 hours to make 270 frames, my computer is an AMD Ryzen Threadripper 3970X and NVIDIA GeForce RTX 3090.
I will return to the default configuration and try again.
Thanks!!!
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Hi, I'm uploading a few seconds of rendering that I've done with the changes in the size of the sun as Maru advised.
The number of fireflies has been considerably reduced :-) although in some frames the texture of the wall generates a strange noise.
The number of passes that each frame has is 60.
Thanks!
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Which denoising type are you using? Could you try with the Intel AI Denoiser if you are not using it?
I can also see some large-scale flickering on the wall, next to the car. Are you using UHD Cache in "animation (flicker-free)" mode? (Render Setup > Performance > UHD Cache rollout)
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I had Denoise mode on "Corona high quality" and UHD Cache was on Still frame.
Thanks, I'll try what you're telling me.
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Hi, I'm uploading the latest test with the parameters adjusted to what you've told me and I think it's perfect now ^_^
Thank you very much.
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I'd focus on the materials in that area rather than denoising, but I'm no doctor. Maybe duplicate your camera, move it close to that box, and render with that closeup just to see better.
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Thank you. If I don't like the result with the adjustments I've made, I'll try what you're telling me.
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Hi, here is the final result of the render.
There are still some fireflies but this is enough for me.
Regards.
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If this kind of fireflies could not be mitigated using highlight clamping, then I guess the only solution would be rendering more passes per frame.
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Maru, if I use highlight clamping it creates a blur that, although small, eliminates the fireflies but also eliminates the glare from the sun and the light from the charger, which is one of the things we want.
I gave it 70 passes per frame and it took 76 hours to render this 9-second sequence.
Another option that occurs to me is to render at 60 frames per second instead of 30 frames per second.
But for now, the way it looks is enough for us :-)
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Another option that occurs to me is to render at 60 frames per second instead of 30 frames per second.
I am afraid that would increase render time from 76 to 152 hours and the fireflies would still be there. :)
If you wish, we can check your scene and try to come up with some optimizations, maybe this would be helpful for you in future projects. You can contact us and attach it here: https://support.chaos.com/hc/en-us/requests/new
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Thank you :-) you are very kind but I am very crazy and chaotic when structuring scenes and instead of helping me you might start to hate me :-P