Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: soso on 2019-07-04, 15:29:54

Title: Corona 4 fireflies
Post by: soso on 2019-07-04, 15:29:54

Stil having firefly won't disappear problem with Corona 4 Hotfix 1. Even without caustic solver, without any caustics in material, and noise level at 4.76% it still won't disappear.

Successfully uploaded as 1562247089_firefly.7z.

Title: Re: Corona 4 fireflies
Post by: maru on 2019-07-04, 16:20:04

Thanks for reporting, we will look into this!

Title: Re: Corona 4 fireflies
Post by: maru on 2019-07-10, 11:41:57

In this case the fireflies are actually expected. See this guide: https://coronarenderer.freshdesk.com/support/solutions/articles/5000529356
What you can try to overcome them, other than what is advised in that guide:
- Using less intensive and less sharp light source (e.g. overcast HDRI instead of Corona Sun)
- Lowering the overall reflection glossiness of the grass material (something as low as 0,3 - 0,4 should work)
- Using Corona Denoiser in "remove fireflies" mode
- Using Highlight Clamping in Render Setup > System (not Highlight Compression in the VFB) - but remember this will kill the high dynamic range in your image if you need to save in 32 bits
- Rendering in double resolution and then reducing

Title: Re: Corona 4 fireflies
Post by: soso on 2019-07-10, 15:40:50

Okay, thanks for the info!