Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: britbunkley on 2023-06-20, 05:27:58

Title: flickering with HDRI
Post by: britbunkley on 2023-06-20, 05:27:58
Hi, I am making a new animation that appears to have flickering almost like caustics on the branches (though there is no water in the scene). It is most obvious in the clip on an upper left tree branch.

I'm using a tree, an animation of a dog and a dome HDRI mapping kloppekloppenheim_05_4k form Poly Haven. (I'll try again with a new 24k version). The animation setting is set to default -secondary solver UDH cache/calculate scratch. The denoiser is set to the default.

Any ideas? I set the dome mapping at a high y-axis offset.
Title: Re: flickering with HDRI
Post by: Aram Avetisyan on 2023-06-20, 10:43:50
Hi,

You have also sent a ticket to us. The case is being handled in the ticket, so please let's keep the communication there.
I will share any important updates here.
Title: Re: flickering with HDRI
Post by: britbunkley on 2023-06-25, 05:52:31
I lowered the noise level limit and raised the precision for the animation, and the rendering (about 30% longer) was much better...acceptable
Title: Re: flickering with HDRI
Post by: Aram Avetisyan on 2023-06-26, 11:39:24
Hi Brit,

You have not replied in the ticket since thursday, but I am glad that you have improvements.
One thing to also note: you were using the displacement with screen size. This will cause flicker in displacement as displacement will be calculated for each frame with different "seed".
Use world size instead to "lock" the displacement in place and avoid flicker.
Title: Re: flickering with HDRI
Post by: britbunkley on 2023-06-27, 00:24:56
Sorry, I never noticed a reply (no mail received). It looks like you were able to download all the files. Can you explain how to "use the displacement with screen size" and ..."Use world size instead to 'lock' the displacement in place and avoid flicker"? I'm not quite sure what this means (I bought the olive tree file.)
Title: Re: flickering with HDRI
Post by: britbunkley on 2023-06-27, 00:51:28
ahh, I Googled it and finally found this link: https://forum.corona-renderer.com/index.php?topic=11299.0 setup > performance settings and change displacement mode from "screen size" to "world size".
Title: Re: flickering with HDRI
Post by: Aram Avetisyan on 2023-06-28, 09:43:42
This is an option for the whole scene, but if you have a modifier on a model, that will override the displacement settings for that model.
I have noticed that the tree had CoronaDisplacementMod modifier and it was still set to "Screen size" in the modifier settings.
You can either set do world size in the modifier settings too, or simply delete the modifier. Make sure you are still getting the desired results before starting to render the animation.