Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: VizRepublic on 2017-06-21, 16:47:33

Title: Animation Anti-aliasing Problem
Post by: VizRepublic on 2017-06-21, 16:47:33
Hello Everyone.

I hope someone can help. I have been running a few animation Tests in order to figure out the animation settings required and am not getting the expected results.

I have attached a 2 videos that shows the anti aliasing issues I am having , unfortunately the video compression makes it look better than it actually is and reduces the severity of it a little.
The issue I am having is that the anti-aliasing is just not crisp and has a lot show a lot of swimming and jittering, especially on the brick wall, pots and glasses. Since this TEST I have run other tests where I have reduced the GI vs AA balance to 8 and 4 as some posts suggests but that just seems to make the result worse instead of improving.

In my latest test(not the one attached) I used Light Portals which made quite an improvement but the anti-aliasing issue is still there, I did not attach that one as the compression made it difficult to see the issue. Each frame rendered at 1920x1080 with 300 passes and a Denoise amount of 0.6.

I am not 100% sure what other settings I should be tweaking to improve this, should I raise the GI VS AA balance? Change Image Filtering? More passes? light samples multiplier? Perhaps its not AA and rather GI that I am not understanding. or is this as good as it gets with Corona?

Any help would be greatly appreciated.

Thank you.
Title: Re: Animation Anti-aliasing Problem
Post by: PEgaz on 2017-06-22, 15:22:17
Hi,

Since always time is an issue - we choose smaller rendering times and workaround with DE:Noise plugin for AE (RE:Vision Effects).
It's not a direct answer to your question, but it solves the problem :)

regards
Piotr
Title: Re: Animation Anti-aliasing Problem
Post by: Juraj on 2017-06-22, 15:33:51
Every fly-through out there literally suffer from this nauseating effect.

What helps most is rendered motion blur. Secondly, no big lateral movements/panning of camera if you only render 30 fps.

But secondly imho implementation of some animation-only temporal anti-aliasing could help. Otherwise the AA no matter how oversampled (you can wait billion years for single frame) will still render the subpixel detail slightly differently.
And imho using large AA filter (3+ px for full HD) is poor solution... modern cameras are crystal clear so why should CGI footage look worse than iPhone from 2005 ?
Title: Re: Animation Anti-aliasing Problem
Post by: Ludvik Koutny on 2017-06-22, 16:49:51
Few important notes:

1, You can make noise stop "swimming" with the camera by unchecking lock sampling pattern. This will make the noise random every frame, but it increases risk of denoiser flickering

2, Noise is not always antialiasing issue. This is extremely important to keep in mind. Only DoF noise, Motion Blur noise, and noise on the edges are antialiasing issues. Noise in glossy reflections, refractions, direct lighting and global illumination is actually sampling noise, not AA noise. So reducing GI/AA balance will make it worse, not better. In your case, it would actually make sense to increase GI/AA maybe even up to 24

3, What's usually most distracting is pixel-perfect noise. Corona 1.6 has blur/sharpen option that will help with this. Just turn it on and leave it at default settings.

4, As Juraj has said, any animated sequence with movement is a lot more pleasant to watch with motion blur.
Title: Re: Animation Anti-aliasing Problem
Post by: maru on 2017-06-22, 17:53:47
What Rawa and Juraj said plus:

-you can try the "jagged edges" fixes I listed here, especially highlight clamping, but only if you can allow it (meaning only in case you do not need 32bpp files with full depth):
https://forum.corona-renderer.com/index.php/topic,16522.msg104046.html#msg104046

-you would need to first determine whether the issue is with insufficient AA or GI samples. If it's AA, then lowering GIvsAA to ~8 and allowing the image to render longer (to get more passes) should help. If it's GI (also glossy reflections/refractions), then increasing GIvsAA should help. (basically what Rawa said)