Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => Topic started by: eilsoe on 2018-06-08, 13:16:21

Title: Possible bug? Triplanared textures are are mirrored in reflections
Post by: eilsoe on 2018-06-08, 13:16:21
This may be a bug, or just me not knowing what the h*ll I'm doing. I can't seems to find a fix though.

I was trying to wrap a car in mud, using a combined model of all the underlying parts with a mud splatter texture on it, and kept getting "black" spots in weird places. After some fiddling, I saw that they were mirrored verions of the wrapped texture. After some more fiddling, I found out that the spots were actually the reflections of the mud layer, only mirrored.

I re-created the issue on a simpler setup. See the attached image for reference.

It's a plane with a simple carpaint material on it, and an instanced plane on top. The instanced plane has a material with displaced lines. The texture I use for displacing the lines is also used as an opacity map. The texture is applied using a triplanar map.

Notice the reflections of the lines on the carpaint. They're mirrored! Using a blendedboxmap produces the same result. A typical plane UVW map does not. Excluding the plane from reflections also cleares the problem, but that's not a usable option.


Any ideas?
Title: Re: Possible bug? Triplanared textures are are mirrored in reflections
Post by: eilsoe on 2018-06-08, 13:23:09
I just realised that it might just be the mirrored backside of the top plane... The reflections still show up even if the planes are the exact same spot.

Is it possible to flag an object / materials as one-sided only?
Title: Re: Possible bug? Triplanared textures are are mirrored in reflections
Post by: maru on 2018-06-08, 13:29:40
The description is a bit too complicated for my tiny brain to comprehend. Can you upload this scene? (or a similar one where the issue can be observed)
Title: Re: Possible bug? Triplanared textures are are mirrored in reflections
Post by: romullus on 2018-06-08, 13:56:12
Is it possible to flag an object / materials as one-sided only?
You can put CoronaFrontBack map in material's opacity slot, set front to white (opaque) and back to black (transparent). That will give you one sided material.
Title: Re: Possible bug? Triplanared textures are are mirrored in reflections
Post by: eilsoe on 2018-06-08, 13:58:48
@romullus: Thanks, I hadn't checked that one out yet :) 

@maru: Sure thing.

I pretty sure it's just the back side of the plane showing through. That would account for the mirrored texture. Corona triplanar seems to only support 3 texture on 3 axis, not 6 on 3, like blendedboxmap. Unless there's a checkbox I missed somewhere :)

2 textures per axis allows me to mirror the opposing side, which eliminates the issue completely.
Title: Re: Possible bug? Triplanared textures are are mirrored in reflections
Post by: romullus on 2018-06-08, 14:02:47
I wonder if fronBack could be used to adress that backside flipping issue? So you would plug your mud texture into front slot, then its reversed version into back slot and then feed the frontBack map to triplanar.
Title: Re: Possible bug? Triplanared textures are are mirrored in reflections
Post by: eilsoe on 2018-06-08, 14:14:11
Well apparently that works just fine, I just checked :D

TIL...
Title: Re: Possible bug? Triplanared textures are are mirrored in reflections
Post by: romullus on 2018-06-08, 15:04:35
It's good to know that there is workaround :] Nevertheless it would be nice if this issue would be fixed in the next version.
Title: Re: Possible bug? Triplanared textures are are mirrored in reflections
Post by: eilsoe on 2018-06-11, 10:38:40
Absolutely. It'd be nice if the triplanar map had an option to use 6 maps, instead of up to only 3.

I managed to get it right on my car wrapper (see attached image). Still working on it, but I think it's already looking good.