Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: fobus on 2013-12-04, 09:46:03

Title: AA for animation with small details
Post by: fobus on 2013-12-04, 09:46:03
As I knew there is just one option to control Antialialising in Corona. It is the number of passes. Is it right or may be ther is another way to archive high AA settings without increase of sampling all other rays as GI and so on?

Let me explain why I need to high value of AA. Often we need to render animations with very high detailed things like trees or grass. Their details much smaller than one pixel on picture so if we cant sample them well we're getting much noise of AA as you can see at example.
Title: Re: AA for animation with small details
Post by: maru on 2013-12-04, 10:13:19
To get better AA you should actually reduce path tracing samples. :)

You can also try rendering in higher resolution and reducing.
Title: Re: AA for animation with small details
Post by: fobus on 2013-12-04, 10:53:46
I tried some different settings PTS/Passes. In first try (http://forum.corona-renderer.com/index.php?action=dlattach;topic=2149.0;attach=8222;image) it was 4 PT samples and 200 passes. Quite noisy at my opinion. 640*360px  90 sec per frame.

The second try was 4 PT samples and 400 passes. It is noisy too and was 125 sec per frame (Corona-AA-Test_4-400.gif).
And the third was 1 PT sample and 1000 passes for ultimate AA. Noise still there but it is acceptable for my taste. (Corona-AA-Test_1-1000.gif).

Title: Re: AA for animation with small details
Post by: Ondra on 2013-12-04, 10:54:57
you can also try to increase image filter blur, maybe that is more acceptable than the noise
Title: Re: AA for animation with small details
Post by: fobus on 2013-12-04, 11:00:40
you can also try to increase image filter blur, maybe that is more acceptable than the noise

No. It is just blurs the noise. Details lost, noise still there but blured. No option.
Title: Re: AA for animation with small details
Post by: Ondra on 2013-12-04, 11:39:45
in that case, since Corona does not offer prefiltering of geometry, the only way to solve this and not modify the scene is just to decrease PT samples and wait for it ;)
Title: Re: AA for animation with small details
Post by: Ludvik Koutny on 2013-12-04, 11:47:05
PT samples is a tradeoff value. So lowering PT samples will mean more samples will go into AA at the cost of GI quality.
Title: Re: AA for animation with small details
Post by: fobus on 2013-12-04, 12:26:47
in that case, since Corona does not offer prefiltering of geometry, the only way to solve this and not modify the scene is just to decrease PT samples and wait for it ;)

Hmm... 1000 passes is the only way to reach quailty of AA in that case. Interesting how much time it will be in real scene with lots of geometry, GI and so on... I'm scared in advance o_O
Title: Re: AA for animation with small details
Post by: maru on 2013-12-04, 15:16:59
How about rendering in higher resolution (2 or 3 times) with normal PT value and then downsampling?
Title: Re: AA for animation with small details
Post by: fobus on 2013-12-04, 16:01:01
How about rendering in higher resolution (2 or 3 times) with normal PT value and then downsampling?

I think it is no quicker than render it with high AA settings, but you'll need way too much GBs of sequences if render it in 2160p compared to 1080p for example. And compositing of such huge files will be a big pain in .ss.
Title: Re: AA for animation with small details
Post by: Ondra on 2013-12-04, 16:04:12
yes, the way monte carlo works you will get the same amount of noise when rendering to 2* resolution and downsizing, as when rendering in the lower resolution for the same amount of time