Corona Renderer Forum

Corona Renderer for Cinema 4D => [C4D] I need help! => Topic started by: Konichowaa on 2020-07-02, 11:43:50

Title: Image after denoising
Post by: Konichowaa on 2020-07-02, 11:43:50
Hi I'm having a project where the image turns (partially) black after denoising, when I render in high-res.
During the preparation of the file, I have rendered many times without problems in lower resolution.
For the high-resolution it seems fine while rendering passes, but at the end it becomes blacked out

Thanks for any help...

PS: same results on renderfarm

best regards, Koen
Title: Re: Image after denoising
Post by: TomG on 2020-07-02, 14:21:32
Did you get any warnings about NaNs? Any warnings about low memory (and did you check that you are not running out of memory, even if there was no warning at the start of the render)? Also, in order to help we always need to know which version of C4D, which OS, which version of Corona.
Title: Re: Image after denoising
Post by: beanzvision on 2020-07-02, 15:01:37
And is Bloom and glare being used at all?
Title: Re: Image after denoising
Post by: Konichowaa on 2020-07-02, 15:22:07
hi guys,

yes bloom+glare is used, but no other settings than usual;
bloom intensity 0.5
glare intensity 0.05
color int 0.3
color shift 0.5
treshold 1
streak count 3
rotation 15
streak blur 0.2

I got 128GB RAM, but I must check during a render if it runs up that high. It is not a very complicated scene this time, so it would surprise me, nonetheless I will check

Renderfarm also looked into it just now and they came up with a physical glass material (that I also use for several years) that when being removed it renders fine?! and also maybe due to use of coffee tags and espresso tags (these last I certaily cannot live without...) I removed the coffee tags and resend without success. Espresso tags must remain because they drive entire structure of the props

My version is R19, corona 5 (last hofix 3?) because of use with renderfarm, I cannot yet update to 6

Title: Re: Image after denoising
Post by: TomG on 2020-07-02, 15:48:26
TY for all the info! Sounds like NaNs for sure - if NaNs are present in an image, Bloom and Glare makes them spread across the whole image into large dark patches (it's not a problem with Bloom and Glare as such, just that if a NaN is in there as a single black pixel, it will cause it to spread across large areas of the image). Glass is more likely to cause NaNs. Surprised you didn't get a warning message about it, anyway, the best thing to do in that case is to send us the problem scene. NaNs are always a render engine error, so we need to look into why they are happening so that it can be fixed.
Title: Re: Image after denoising
Post by: Konichowaa on 2020-07-02, 16:08:17
Thanks TOm,
meanwhile I tried this too:

removed coffee tags without succes

Memory uses about 20GBof the installed 128GB

Unchecking Bloom & Glare didn't help,

however unchecking Sharpening DID!! even with bloom & glare benabled again

I wll try so send you the file ASAP

Thank you both for pointing this out, I would never think it was related to those features...
Title: Re: Image after denoising
Post by: TomG on 2020-07-02, 16:39:37
Just for clarification, it probably isn't either of those features at all, just that both of those features are taking a small number of NaN (which is "Not a Number" if you haven't run into it before) black pixels and spreading them across the image. With them off, you probably have one black pixel someplace (and if you right click on that pixel in the VFB, it will say "NaN"). That is, neither sharpen and blur nor bloom and glare are at fault, but the render calculations in the scene are. We can check for sure once we have the scene, ty for being able to send that in!