topic Re: UV maps seemingly messing up when exporting to .obj in 3ds Max Modeling Forum

UV maps seemingly messing up when exporting to .obj

Anonymous — Tue, 12 Nov 2019 11:57:11 GMT

I have a model in .max format and I wanted it to be exported to a more universal format (such as obj) so I could use it in Blender, the issue is that in 3DS Max the uv mapping seems fine,

but when exported the positioning of the texture seems to be messed up.

Re: UV maps seemingly messing up when exporting to .obj

10DSpace — Tue, 12 Nov 2019 15:13:20 GMT

I suggest trying the .fbx format for export from max and import into Blender. Generally, IMHO it is a better format for export and import across platforms. Good luck.

Re: UV maps seemingly messing up when exporting to .obj

Anonymous — Tue, 12 Nov 2019 15:38:11 GMT

Unfortunately this seems to produce the same issue. But thank you for your reply.

Re: UV maps seemingly messing up when exporting to .obj

10DSpace — Tue, 12 Nov 2019 16:00:14 GMT

@Anonymous

And when you compare the UVW map from 3ds Max from UVW Unwrap to the Blender imported version they appear to be identical? Sometimes if the UV map in Max has some UV verts outside the 0,1 tile, they will still display properly in Max. Maybe this gets messed up in .fbx export? Also, you get no errors on .fbx export from max?

Re: UV maps seemingly messing up when exporting to .obj

Anonymous — Tue, 12 Nov 2019 16:17:35 GMT

The confusing thing is that it seems to store the uv info in the skin? Since it is a rigged model.

I think this may be vital info in solving the issue

Re: UV maps seemingly messing up when exporting to .obj

10DSpace — Tue, 12 Nov 2019 17:05:33 GMT

The confusing thing is that it seems to store the uv info in the skin? Since it is a rigged model.

I think this may be vital info in solving the issue

No, as far as I know there is no way for UV info to be stored in the skin modifier. The UVW Unwrap modifier should have been applied before the skin modifier and then collapsed. Any time you place the Unwrap UVW modifier on the mesh, it will reveal the UVW map. You simply do not have it in the modifier stack right now from your picture.

To figure out what happened I suggest the following:

1. Make a copy of your 3ds max file and work on that.

2. Pplace the Unwrap modifier right above the mesh and open the editor to see the UVW map. If it looks good with an orderly layout of UVs and no overlapping UV verts/faces then close the editor.

3. Turn off the skin modifier in the stack by clicking the eyeball next to it.

4. Select the mesh and export it via .fbx using Export selected.

5. Import the .fbx mesh into blender and see if this time the model texture seems to be placed properly. If not, check the Blender UVs to see if they look the same as what you saw in Max.

Re: UV maps seemingly messing up when exporting to .obj

Anonymous — Tue, 12 Nov 2019 18:47:23 GMT

Here is the apparent UV map in 3ds max and then blender, looks like part of it isn't even on the map in blender and may be in the wrong position, the texturing on the model is definitely wrong.

EDIT:

I also got this error

looking at the blender image of the UV it looks like it expects the texture to be mirrored or something? (based on the teeth section)

Re: UV maps seemingly messing up when exporting to .obj

10DSpace — Tue, 12 Nov 2019 19:07:21 GMT

With the exception of the one UV island off on it's own in Blender, the UV islands in both max and blender correspond in position, although the Blender version has lost the correct aspect ratio (i.e., instead of a square like 2048 by 2048 it is a rectangle that looks twice as tall as wide). What is the aspect ratio of the actual texture map you are using?

I also wonder whether that UV island that is off on it's own and looks like a butterfly, is actually in the wrong UV tile in Max. I could not find that same butterfly shape in the max UVW Unwrap that you sent so maybe it is in another UV tile that your view does not include. To check this, go back into max and open the UV editor. In the upper right hand corner there is a checkered icon that enables the option "Show the multi-tile in the dialogue", click on this to enable multi tile display. Can you find the butterfly shaped uv island?

Regarding the error message, is your Unwrap UVW modifier above the skin modifier? it should be below it, just above the mesh.

Re: UV maps seemingly messing up when exporting to .obj

Anonymous — Tue, 12 Nov 2019 19:48:06 GMT

I moved the unwrap below it now, here is the screenshot of what was asked

Re: UV maps seemingly messing up when exporting to .obj

10DSpace — Tue, 12 Nov 2019 20:48:15 GMT

OK, now all you have to do is correct the UVW map in max and re-export to .fbx, this time enabling the skin modifier. However, note that

if you move any of the "good "uv islands in the u1v1 tile your texture map will be off. So, to avoid this, check first to see what the errant uv islands correspond to in your mesh. If it is not an important part of the mesh you might get away with scaling them down and dragging them to an unused part of the u1v1 tile being careful not to perturb any of the other uv islands. It is critical that this all be done with the uvw unwrap modifier right above the mesh, but below the modifier stack. Hope this works for you.

Re: UV maps seemingly messing up when exporting to .obj

Anonymous — Tue, 12 Nov 2019 20:53:20 GMT

I have no idea how to fix this, there is a texture I found that is a butterfly version that -seems- to fix most of it but then the eye is also off in terms of positioning for an unknown reason?

Despite the textures being shown to be lined up and correct the result given is nothing alike, is this not some sort of bug?

Re: UV maps seemingly messing up when exporting to .obj

Anonymous — Tue, 12 Nov 2019 22:48:15 GMT

I managed to solve the problem by just creating "butterfly" versions of the textures by duping them and flipping the duped part horizontally.

example

original

edit

basically it appears 3ds max was doing this mirroring on the original texture, but failed to transfer this over when it was being exported, so it was manually introduced.

Re: UV maps seemingly messing up when exporting to .obj

10DSpace — Tue, 12 Nov 2019 23:14:51 GMT

Glad you were able to solve the problem.

Re: UV maps seemingly messing up when exporting to .obj

Anonymous — Tue, 12 Nov 2019 23:16:07 GMT

Thank you for your help, I appreciate it 🙂