import/export OBJ from Max ruins UV's

[duffman999]

Hi guys, I’ve been looking into ZB for a while now and finally started using it and have already run into some difficulty. Looking into a lot of the threads around here have been helpful but I think there is some setting that I’m overlooking while either importing or exporting an OBJ file from Max9

Below are the before and after versions of the UV’s (I’m new to unwrapping, so I make no claims on it being ‘good’ before it is messed up). Also, I’ve included the settings for importing and exporting. For this test, I didn’t even use ZB, I just exported it and then imported the OBJ in a new file in Max.

[

It seems that the vetecies are unmoved, but the faces are all over the place, and many vertecies are in multiple places and need to be target welded back to where they were. I’ve read that max renumbers the verticies sometimes, but I assumed a base mesh made in max would not have that problem.

Has this happened to anyone else? I’ve read the ZB wiki and a lot of this site and can’t seem to find the answer, so maybe some of the experts here can help?

I’ve tried toggling the Unify/Obj smooth groops/use materials on the import side and tried different settings on the Group by/Faces/# of digits on the export side = I’M LOST

Thanks a bunch in advance for any help:D

Attachments

[aminuts]

I do believe that the zbrush wiki and here in the tutorials section there are Zbrush to Max or vice versa…tutorials and how to’s…I have seen some mention of having to turn some setting up but cannot recall what that is…I don’t have Max so wasn’t important to my head I reckon.

[duffman999]

Yeah, there’s a ton of stuff around here about standard import/export to max settings, a lot of which I’ve tried, but not much about troubleshooting like this.

Anyway, I think it’s an importing problem: I opened up the file in ZBrush and applied GUVtiles just to change the mapping, and when I imported it again in max, all of the internal verts on the group grids were actually four copies superimposed on top of one another, each coming from one of the adjacent verts. This was actually easy to fix (weld) but it doesn’t help me for meshes I want to unwrap myself.

I guess I’m still holding out for a hero here, because I’m starting to get discouraged - I wanna play with ZBrush!

[n-drew]

afaik max changes the vertices numbers. try the “relative vertice numbers” option AND/OR change the “file: #of digits to 6”. (i bet the last one is the problem)

dunno what option does help so you have to check it out.

[system]

Looks like the quads are all getting reduced to triangles. Maybe export as triangles? Does Zbrush support quads?

[Boa]

I don’t think that your UVs are ruined. It looks like two things happened here.

First: It seems that you exported from ZBrush with the Tri option set in the export settings. I usally have the Qud option on.

Second: The UVs of a reimported .obj are split apart in Max. I don’t know a way to avoid this on reimport from ZBrush, but this must not represent a problem with rendering.

But if you want to reunit your uvs again, apply an Unwrap UVW modifier, select all UVs in the Edit UVWs window and scale them up portonially and set the Weld Treshold in the Unwrap Editor Options to 0.01. The aim here is to scale the smallest part of your UVs big enough to escape the treshold. Then click Tools/Weld Selected. Result: all UV verts that laid on top of each other are welded and the UVs would look the same as before Zbrushing if you had exported with the Qud option.

Hope this helps a bit,
Andrea

[duffman999]

Thanks for your response Boa, but as I said, ZB was not used at all for this. I just exported and imported right back into max.

I did try to weld everything together, but it just permenantly made the UV’s into tris, while the actual mesh is still quads (I suppose I should have made that clear before).

A little more playing around with different settings and hopefully I’ll stumble across the answer, but until then I might have to just use GUV and try to make it work.

Maybe people can just start throwing out some WAGs (Wild Ass Guesses)?

[XzEBiX]

hi duffman999, I have a problem like you have, it would be great if you would send me the solution (in the thread) if you’ll find one. So I can’t help you by now, maybe Im going to find out something about how to set up for 3dsmax and ZB3 to do not lose the UV-Settings.
bye
XzEBiX

[SimonTG]

Ive been getting the same problem on my last 2 models, just cant figure it out… If anyone has a solution it would be greatly appreciated.

[Bodybag]

me too,please help

[SimonTG]

Well… It doesnt make much sense but I fixed my problem on 1 of my models by aplying 3 reset xform one after another :rolleyes: It exported as an obj without any problem afterward.

[system]

i have finally figured it out. I was having the same problem. if you are having this problem. use the reset xform. once you do the normals will be inside out. just reverse the normals and your good to go.