Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Lnt on 2018-01-10, 09:12:39

Title: Perfectly white background
Post by: Lnt on 2018-01-10, 09:12:39
Hello,

So im trying to do a "furniture spin animation", which means a simple piece of furniture being rendered for 15 frames while spinning around on a white plane
However, because of the HDRI that im using, the background is grey and not white, which would normally not be a problem since i would mask it in photoshop, but since theres so many renders, it will be time consuming.

So how can i remove the plane that the furniture is on from the renders, while still keeping the shadows that are being cast on it?
Also, is there a way to turn the HDRI invisible to the camera? to keep it affecting the object while not appearing at all in the render?

Hope that makes sense, thank you.
Title: Re: Perfectly white background
Post by: faust on 2018-01-10, 09:19:30
If you're using ShadowCatcher Material change Direct visibility Override to White, if not, just use Rayswitch material for plane with White color in Directly visible slot
Title: Re: Perfectly white background
Post by: Nejc Kilar on 2018-01-10, 09:25:30
I'd use a ShadowCatcherMTL for the ground / cyclorama and override the environments direct visibility with a color set to pure white.

That should work :)

edit: beat to it, kudos to ya Faust!
Title: Re: Perfectly white background
Post by: Lnt on 2018-01-10, 10:11:36
@nkilar @faust

Thanks for your replays,
however, i havent managed to get the right result yet
first time im using shadowcatcher and i might do this wrong

How my set up is right now

Render>Environment = My HDRI
F10>Environment Override>Direct visibility = corona output with a white corona map into Imput
My background = CoronaShadowCatcher with a white Corona Color into Backplate

i m doing something wrong
Title: Re: Perfectly white background
Post by: romullus on 2018-01-10, 10:19:14
Hi Lnt,
you may want to look at this topic: https://forum.corona-renderer.com/index.php?topic=11345.0 and download the scene provided there. It's slightly outdated, but you still might find some inspiration in it.
Title: Re: Perfectly white background
Post by: maru on 2018-01-10, 10:34:52
So how can i remove the plane that the furniture is on from the renders, while still keeping the shadows that are being cast on it?
This is a typical use case for the shadowcatcher material.

Quote
Also, is there a way to turn the HDRI invisible to the camera? to keep it affecting the object while not appearing at all in the render?
Render Setup > Scene - direct/reflect/refract overrides.
Title: Re: Perfectly white background
Post by: Lnt on 2018-01-10, 10:41:04
@romullus
Thanks, i downloaded your file and notice my mistake
Everything was ok on the material side, however i had a 5 on Highlight Compress in tone mapping and everything was getting a grey shade that i didnt notice.

Thank you all, you're awesome.
Title: Re: Perfectly white background
Post by: Fluss on 2018-01-10, 11:17:56
Quote
Also, is there a way to turn the HDRI invisible to the camera? to keep it affecting the object while not appearing at all in the render?
Render Setup > Scene - direct/reflect/refract overrides.

Wouldn't suggest that as reflection and refraction overrides are broken and generate a lot of noise.
Title: Re: Perfectly white background
Post by: Njen on 2018-01-10, 19:33:05
Wouldn't suggest that as reflection and refraction overrides are broken and generate a lot of noise.

Wait, what!? I wasn't aware of this issue, has it been reported?
Title: Re: Perfectly white background
Post by: maru on 2018-01-11, 09:37:17
Wouldn't suggest that as reflection and refraction overrides are broken and generate a lot of noise.
Wait, what!? I wasn't aware of this issue, has it been reported?
Yes, unfortunately this is a serious issue, which seems to be hard to fix. On the other hand, in some cases it may not be noticeable or present at all.
Bug report: https://corona-renderer.com/bugs/view.php?id=2124
Forum thread: https://forum.corona-renderer.com/index.php/topic,13104.0.html
It is a part of "light transport issues", but I will be sure to add it explicitly to "known bugs and limitations" list at https://coronarenderer.freshdesk.com/support/solutions/articles/5000516180-known-bugs-and-limitations