Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: danielhagene on 2016-10-12, 14:27:52

Title: Light Leaks in Corona 1.5?
Post by: danielhagene on 2016-10-12, 14:27:52
I'm getting light leaks when rendering a scene. The leaks are understandable at the edges of the wall, but the columns are solids sticking trough the roof - so there shouldn't be any leaks.

Did not have this problem in 1.4. Does every surface have to be "shelled" in order to not get leaks, or is this just a bug?
Title: Re: Light Leaks in Corona 1.5?
Post by: danielhagene on 2016-10-12, 14:31:55
I put a shell-modifier on the roof and walls, seems to have fixed it. But it's not something I would want to do in every scene.
Title: Re: Light Leaks in Corona 1.5?
Post by: Ludvik Koutny on 2016-10-12, 17:51:37
Could you try to install 1.4, open the same scene and see if it renders same, or if those artifacts get better? Thanks!

Someone reported a very similar thing just two posts above you, and it would be very unfortunate if this was some regression in Corona 1.5
Title: Re: Light Leaks in Corona 1.5?
Post by: Cyanhide on 2016-10-12, 18:05:45
I'm getting light leaks when rendering a scene. The leaks are understandable at the edges of the wall, but the columns are solids sticking trough the roof - so there shouldn't be any leaks.

Did not have this problem in 1.4. Does every surface have to be "shelled" in order to not get leaks, or is this just a bug?
Even in 1.4 if my ceiling wasn't shelled I would get light leaks.
Same goes for the floor.
Title: Re: Light Leaks in Corona 1.5?
Post by: Alexandre Besson on 2016-10-12, 19:15:47
Same issue.
Title: Re: Light Leaks in Corona 1.5?
Post by: maru on 2016-10-12, 20:13:42
I haven't seen such thing in a while... Some wild guesses:
-are you using bump or normal maps on any of the objects with the leaks?
-are you using glossy reflections on them?
-is the scene modeled in proper scale?
-is the scene far away from 0,0,0 world coordinates?
-are you using rounded edges on any of the objects?
Title: Re: Light Leaks in Corona 1.5?
Post by: Jpjapers on 2016-10-12, 22:47:09
I have the same issue. Its a no on all fronts for my scene Maru. happens with a max standard grey shader on ceiling columns and where the walls intersect the ceiling too. Modelled in mm accurate scale and centered on the origin. I noticed it a couple of days ago but thought it was maybe because i wasnt leaving it to render enough before denoising. Ive also noticed that there seems to be alot of colour cast in corner shadows (where AO would happen)  that looks very unnatural.
Title: Re: Light Leaks in Corona 1.5?
Post by: Jpjapers on 2016-10-14, 10:14:33
Has anyone in the team managed to replicate this problem?
Title: Re: Light Leaks in Corona 1.5?
Post by: Ondra on 2016-10-15, 00:24:38
no, we have not seen any regression in our test suite, and we have several scenes focused on light leaks in there. So any scene where the effect is significant would be appreciated ;)
Title: Re: Light Leaks in Corona 1.5?
Post by: Jpjapers on 2016-10-15, 11:29:20
Unless someone else sends you one i can upload one on monday. could you post the link to the upload area? Thanks :)
Title: Re: Light Leaks in Corona 1.5?
Post by: Ondra on 2016-10-15, 11:39:57
http://corona-renderer.com/upload
Title: Re: Light Leaks in Corona 1.5?
Post by: Fluss on 2016-10-15, 16:03:51
I've experienced that issue about a week ago.

Edit: and on my current scene
Title: Re: Light Leaks in Corona 1.5?
Post by: Fluss on 2016-10-16, 20:04:00
After some further tests

I haven't seen such thing in a while... Some wild guesses:
1-are you using bump or normal maps on any of the objects with the leaks?
2-are you using glossy reflections on them?
3-is the scene modeled in proper scale?
4-is the scene far away from 0,0,0 world coordinates?
5-are you using rounded edges on any of the objects?

1- yes, bump map but the issue still happens without bump
2- yes
3- yes
4- no, centered on 0,0,0
5- no

Issue seems to happens only when any object (with tickness or not) is intersecting another one with no thickness AND in the angles of objects with no thickness (welded vertices).
Title: Re: Light Leaks in Corona 1.5?
Post by: MartinBrinks on 2016-10-18, 10:19:37
I have just experienced light leak on a former 1.4 scene when using 1.5, a scene that rendered fine before. I'll see if I can upload a cropped part showing it later (it's an NDA kinda project).
Title: Re: Light Leaks in Corona 1.5?
Post by: maru on 2016-10-20, 14:20:33
Sorry, but I did not manage to reproduce this. I am only getting leaks in a form of tiny single bright pixels, in both 1.4 and 1.5, but I guess this is expected when the room has no thickness Shell modifier fixes this instantly.

An example scene would be appreciated!
Title: Re: Light Leaks in Corona 1.5?
Post by: Juraj on 2016-10-20, 14:48:32
I noticed it actually too. I will hunt for some picture examples.

In my case it doesn't happen in thin surfaces, I use none. Ever. My case is in windows which barely touch the frame, previously there would be shadow, now occasionally, a light manages to come through.
Title: Re: Light Leaks in Corona 1.5?
Post by: quizzy on 2016-10-25, 15:14:57
I just experienced it as well, when a thin (shelled) object crosses a thicker (shelled) object.
Title: Re: Light Leaks in Corona 1.5?
Post by: maru on 2016-10-25, 19:15:37
We have already received a number of reports about this, and sample scenes, so we are actively looking for an explanation and solution.