Animation: noisy edges

[grafichissimo]

Hello guys.
recently I start doing some animation in Corona.
As always Corona is fast and easy to use, there is just one thing I can't sort it out.
Lets' say I want to render a static car with moving cameras.
For the illumination I use an HDRI and a series of corona light mapped with  a gradient texture.
Lets' say I want to use the denoiser, at this point the big issue I find is that while I can get nice and clean surface in a reasonable time I can't get clean edges, there is always a evident flickering and the denoiser doesn't work consistently.
SO my question is, how do I get clean end consistent edges in a reasonable rendering time?

The render attached is a 45 minutes render frame, quite a lot and still when I play some frame I can see slightly flickering in the point I have marked.

[maru]

It looks like there might be some overlapping faces in that area, or maybe you are experiencing something similar to this:
https://coronarenderer.freshdesk.com/support/solutions/articles/5000529356-i-can-see-bright-pixels-in-grass-
Remember that denoiser is not a magic wand - it will try to remove noise, but may sometimes fail, especially if the noise is too strong before denoising.

You can also try lowering GIvsAA (to increase the quality of antialiasing), or increasing it (to increase the quality of GI), and run some test renders to see if there is improvement.

[grafichissimo]

What I have done after a few test is this:
Using denoiser I have reduced the Gi vs AA and I notice a big improvement Clamping the Highlight, maybe to mach, but I am quite happy with the result.
Between 5 and 6 minutes per frame on 1 machine.

Post in after effects for the clip.
The frame is the original render from max without post.

[maru]

Setting LSM to 0 is not a good idea - you will most probably end up with noise in direct light sooner or later. :)
Highlight clamping probably does the job for you - but the drawback is that you lose highlight intensity and everything will be clamped if you save to 32 bits.

[SharpEars]

Setting LSM to 0 is not a good idea - you will most probably end up with noise in direct light sooner or later. :)
Highlight clamping probably does the job for you - but the drawback is that you lose highlight intensity and everything will be clamped if you save to 32 bits.

I don't know why a slight amount of bloom is not suggested to help with aliasing (instead of clamping).

[Ludvik Koutny]

Bloom won't help, because it does not have an exponential falloff, but glare will. And if you get problems with sharp streaks from glare, you can always increase glare blur parameter. Would be good if bloom in future had option for exponential distribution, like glare does.

[SharpEars]

Bloom won't help, because it does not have an exponential falloff, but glare will. And if you get problems with sharp streaks from glare, you can always increase glare blur parameter. Would be good if bloom in future had option for exponential distribution, like glare does.

And glare has the problem that not all blown out highlights will have a glare effect to them regardless of the Corona VFB settings/thresholds. So, maybe a combination of both is the best approach. Or, maybe there is a good way to do it using the EXR in Photoshop that I am not aware of, which can take into account values much larger than 1.0 for a fake bloom/blurry glare

[Ludvik Koutny]

Bloom won't help, because it does not have an exponential falloff, but glare will. And if you get problems with sharp streaks from glare, you can always increase glare blur parameter. Would be good if bloom in future had option for exponential distribution, like glare does.

And glare has the problem that not all blown out highlights will have a glare effect to them regardless of the Corona VFB settings/thresholds. So, maybe a combination of both is the best approach. Or, maybe there is a good way to do it using the EXR in Photoshop that I am not aware of, which can take into account values much larger than 1.0 for a fake bloom/blurry glare

That's not a problem, that is correct. Glare is based on the intensity, if the highlight is just a little bit above 1, then glare won't be there, and it would not be there in real world either. At the same time, if the highlight is just a little bit above 1, then it won't produce strong aliasing.