Author Topic: Some faces appear flipped in Painter  (Read 1483 times)

Hi everyone,

I have a problem with my phone box model that I'm texturing. It seems that the faces of my mesh that make up the window panes are flipped.
If you look at the attached image, you can see that the windows appear to be see through and that 2 areas with the same material facing in the same direction produce different shading. For the modeling I used Blender and I made sure that every normal is facing in the right direction. Heck, because it did not work with the properly set up normals I even tried flipping the problematic faces to see what happens but I got the same result. Which is extremely strange because how can these faces only ever look in one direction regardless of the normals I set up during modeling, right?

Each window is made up of 2 large faces, intersecting with the window frame, one of the faces facing outward and the other one facing inward.
Is it possible that the problem is caused by the fact that these face pairs as too close to each other and they cannot be displayed correctly?

I also attached the .fbx, hopefully you can help.

Many thanks in advance!! :)
Last Edit: December 11, 2015, 02:47:51 pm

Hey pacsuta.david,

What I find really strange is that your screenshot looks like you modeled every window independently, but you just have two big planes as windows.
Therefore I think this is a masking issue. Are you sure you have not masked something wrong or so?

Bringing the model and the textures into your target engine, does the issue persist?

Best Regards
Environment Artist - Twitter

I'm afraid that's a face sorting issue related to the transparency system that we use. Your mesh itself is fine.
There is no easy solution unfortunately.
Don't forget your log file. It can be exported from the Help menu of the software.
Fabrice Piquet aka Froyok. Product Manager, Technical Artist and Documentation at Adobe.

Hi Fabian, Froyok,

thank you for your answers.

Because it's a uni assignment, target engine is just Marmoset. So I brought the model and textures into Marmoset and I have the same issue there.
So clearly there must be something wrong with my textures and there you go, the problem only occurs with the normal map applied. I added two more images from Painter - one with the normal map (obvious transparency) and one without the normal map (faces show up correctly - opaque).

I'm going to try to see if there's anything I can fix about my cage or the high poly and then rebake but that takes some time so in the meantime I was wondering:
Would it solve the problem if I flipped one of the channels in the problematic areas of the normal map? Do you guys have any other suggestions?

Thank you for your continued support!
Last Edit: December 11, 2015, 01:43:01 pm

If it's a baking issue, then try to lower your rear distance in the baker settings. Or to extend the gap between the faces that you use for the glass material.
Don't forget your log file. It can be exported from the Help menu of the software.
Fabrice Piquet aka Froyok. Product Manager, Technical Artist and Documentation at Adobe.

Thanks Froyok, what I actually did is that I moved the high-poly plane just slightly away from the low-poly (maybe there was some z-fighting going on during baking because they were just 2 planes in the exact same position?) and I also found that my high-poly had some loose verts. I didn't use any ray-cast distance because it was a caged workflow - anyway I rebaked the whole thing and everything is rendering correctly now. There was no need to extend the gap between the faces.

I never thought a normal map could completely flip a face. This was an interesting learning experience for me.

Sorry to give you all the trouble when the issue wasn't even with Painter in the first place.
Thanks again for your help and kudos to all of you at Allegorithmic for your work.

Edit: Oh and compared to the newly baked normal map, the errors quickly become obvious in the previous one!:)
Last Edit: December 11, 2015, 04:06:18 pm