Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] I need help! => Topic started by: Assyl on 2021-12-26, 17:16:12

Title: distortion of the material when rendering
Post by: Assyl on 2021-12-26, 17:16:12
Hey! Can you tell me why it appears and how to get rid of it?
Title: Re: distortion of the material when rendering
Post by: burnin on 2021-12-26, 18:15:38
If you mean distortion you get on the roof tiling, it's called Moire Pattern (https://en.wikipedia.org/wiki/Moir%C3%A9_pattern)/Effect.

V-Ray Example: Anti-aliasing Filters and Moire Effects (https://docs.chaos.com/display/VMAYA/Image+Sampler+%7C+Anti-Aliasing#ImageSampler|Anti-Aliasing-Example:Anti-aliasingFiltersandMoireEffects)

You can somewhat get rid of it by couple of different techniques - either using "right" AA Filter (https://coronarenderer.freshdesk.com/support/solutions/articles/5000516725-how-to-control-antialiasing-in-corona-renderer-) or "Super-sampling" (render bigger image and after down-scaling it).

Title: Re: distortion of the material when rendering
Post by: Assyl on 2021-12-27, 14:56:08
This is a profiled sheet. Why does the corona material fit like this? I mean these incomprehensible circles.
Title: Re: distortion of the material when rendering
Post by: Beanzvision on 2021-12-27, 15:14:51
This will even happen with standard C4D materials. Did you try the recommendations above? What size is your render, have you tried increasing it also?

(https://forum.corona-renderer.com/index.php?action=dlattach;topic=35217.0;attach=158758;image)
Title: Re: distortion of the material when rendering
Post by: Assyl on 2021-12-28, 16:58:53
The geometry is correct. Higher resolution doesn't help. The number of passes is the same. the solution should be simple.
Title: Re: distortion of the material when rendering
Post by: BigAl3D on 2021-12-28, 21:02:39
You are definitely running into the Moiré effect. This was always a concern with broadcast video since the resolution was so low (720x486). The angle of your lines plays a big part in it as well. The only solution is to change the angle, enlarge the pattern or increase the resolution. The image that Beanzvision posted is spot-on. The scaled-down image doesn't have the resolution to resolve the detail and it conflicts with the screen's pixels. This is why top professionals on TV never wear fine patterns on camera. Their clothes will dance with this effect. In this example, notice the farther away the camera gets (lower effective resolution), the worse the shimmering gets? Same problem you have here.