Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: sculptera on 2016-11-14, 19:38:38

Title: Corona light issue
Post by: sculptera on 2016-11-14, 19:38:38

Hi guys,

Ive noticed a strange phenomenon using Corona area lights. Visibility is turned off, while visible in refl/refr is on.
When rendering at a smaller test resolution, behavior is to be expected. However, when increasing the resolution, the light loses its illumination component, but appears the spec is still there. This is occuring on Corona version: 1.5
Full-speed, Non-debug, MaxSDK 2012
Build timestamp: Oct 10 2016 10:58:59
Defines: Wide RGB


Is there something Im doing wrong? Unfortunately, im using Max 2012 and have not upgraded.  This is occuring on multiple scenes. I will try deleting the light and creating a new one to see if that solves it.
Attached is an image showing the buffer at 1536 res, and the one next to it is 3k.

Thanks for your help!

Title: Re: Corona light issue
Post by: romullus on 2016-11-14, 20:04:05

Are you sure it's not material issue, becauseit seems the only thing that is affected, is that rightmost object. Can you do this test wit default Corona material override?

Title: Re: Corona light issue
Post by: sculptera on 2016-11-14, 22:19:08

You are right. It appears to be material based.
Is there anything in particular I should check for? My mat seems to be set up the same way as the rest of them. Im using the PBR workflow from Substance using CoronaMix in the IOR. Everything has worked amazing until this point.
Thank you!

Title: Re: Corona light issue
Post by: romullus on 2016-11-14, 22:29:15

I don't know, maybe it has some very fine and very strong bumb, that changes materials appearance on different resolutions due to filtering? Can you show screenshot of that material, maybe that would give some clues?

Title: Re: Corona light issue
Post by: sculptera on 2016-11-18, 21:37:54

Hey Romullus,

Sorry for the delay. Ive been working against a deadline. Ive narrowed down to UV mapping. It seems a standard box mapping works okay.
Ive tried on a simpler piece where I scaled the UV shells to maximize the 0-1 space and it still does it. I just cant win.
I'll post a shot of the material asap. Very simple mat.

Title: Re: Corona light issue
Post by: maru on 2016-11-21, 13:56:40

I am not sure what's going on in the image you posted, but maybe it has something to do with texture filtering? Maybe the bump/some other texture is more blurred when rendering in lower resolution? That's just a guess, and as I said, I don't fully understand the problem.

I can also see that you have bloom and glare enabled. Does disabling it change anything? Maybe the effect just appears different when rendering in different resolution?