Mesh goes black when I rotate it in 3DS...
Hey guys, i've come across an issue in Max 2022(was previously using 2019). I have a mesh that has been triangulated for baking purposes but I want to duplicate a part and rotate it/mirror it to the opposite side. The issue is that when i rotate ANY part of the mesh, it turns black?? The faces look completely normal prior to this. This is giving me some funky issues when I export out into Painter. I have reset transform, applied an Edit Poly on top, Edit normal on top, flipped the faces and nothing has worked. Any ideas? Thanks in advance.
I should note that it occurs when I rotate a part of the whole mesh at the sub-object level. It also happens when I detach a part as a clone, rotate it and then re-attached it to the main mesh. If I rotate the whole entire mesh at object level. It is fine. I cannot assign smoothing groups, it seems the normals are "locked"??
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What GPU are you using? Reminds me of an old Max issue where meshs would disappear if you ran out of / were reaching the limits of your GPU's VRAM, and getting them to re-appear required you to refresh the material. I ran into that issue a lot back 10+ years ago when I was using a Geforce 9800 GTX (which only had 512MB of VRAM).
Maybe try reseting the normals in the edit normals modifier.
Hey there, i tried, nothing happened. I can't even assign smoothing groups to the affected areas for some reason.
I'm using a 2070 RTX, Ryzen 3700, 32GB Ram etc.
Thank you! It worked. I didn't know exactly how the modifier worked and did not know I had to select all the Normals to get it to work. I had to re-apply smoothing groups afterwards which was easy with TexTools.
My question is, why was I getting the issue in the first place? Was it because it was a triangulated mesh? I did not have this issue with any other meshes that were not triangulated. I even check an older model of mine which was triangulated and the same incident occurred? Surely this is an error?
It's not to do with triangulation in a strict sense. I think this issue is that sometimes the vertex normals are locked and aligned to some worldspace transform or otherwise just broken in some way.
when you wrote you can't even assign smoothing groups to the affected areas is a clear indicator the normals are locked and thus the shading cannot be visibly affected. You are actually changing/applying the smoothing groups, you just won't see the shading change.
Thanks heaps. I appreciate it. I've never come across this issue before and I have gone back on completed/baked meshes and duplicated parts before and never had this issues. Is it possible it is a flaw in 3DS 2022??
I've definitely seen exactly the behavior you described over the years multiple times. Some times vertex normals get borked for no discernible reason.
I just did a test on a fresh mesh. Triangulated and exported out. Imported back in and I performed the same function. Got the black faces on attach again! Wonder if this is a bug or exclusive to MAX 2022?
Ah yeah, seems it's a repeatable behavior. Also happens in 2023.
It seems it has nothing to do with triangulating. triangulating either before export with turn to poly or with the FBX exporter options or leaving it as quads, on reimport and attaching the normal issue is present for me.
Thhe only difference for me is the mesh imports back in as an editable mes if I triangulate the model, the method of triangulation is irrelevant, using turn to poly with the fbx triangulation options turned off or just using the FBX options, it comes in as an editable mesh. If I leave it as quads, it comes in as an editable poly.
And it happens even if left as quads? If I triangulate on export, it returns as Editable Mesh also for me. Very strange.
At least for me it doesn't matter about triangulating or even attaching the mesh to anything, just export a mesh with fbx and import it, the normals are locked, then if you rotate it at the subobject level the normals will go whacky. Not sure that's the expected behavior tbh.
Just tried the same, and the same occurred. This is a pretty big flaw...
try exporting with smoothing groups disabled/enabled (depending on how you had it set before)
fbx has more than one way to store normals so might be worth seeing what happens if you force it to use the other one.
could also try toggling the preserve binormal/tangent option as well
I found the solution. On the Import box, it has "smoothing groups" disabled for some reason. I enabled it and the issue was solved! Try it out and let me know if it works for you.
It's the binormal option.
I usually leave it off for what I am doing 99% of the time atm. I dunno how much of a difference it makes to anything, but my thinking has been just let marmoset/substance/unreal recalculate them as they all use the same tangent space, so hopefully it's all matching in engine at the end
Try turning off 'smoothing groups' in the import pop up when you bring a mesh it. It solved the problem for me. Let me know how it goes.