I'm having a problem that I can't seem to solve, partly because I'm at a loss for what has gone wrong.

I've created a mesh in Blender 2.65, applied material groups and UVMapped it.  I can apply a texture based on the UVMap in Blender and it textures fine, everything is where it should be.  However, when I export as an .obj file, then import to Poser, something goes wrong.

The object imports and appears with its material groups intact.  However, portions of the UVmap seem to work properly while other areas of the obj seem to have somehow twisted the UVMap so that textures are out of placed, skewed, or otherwise deformed.  I've remapped the mesh twice in Blender, exported new maps and .obj files, imported again into Poser 6 and it the same error occurs.

I cannot find anything wrong with the mesh and this represents 2 days of work that I don't want to have to scrap and start over.  I can post images if that would be helpful.

Again I'm using Blender 2.65 and Poser 6.  Any suggestions or ideas?  Anyone have any similar problems?

Are you sure all the normals are facing outward?

Yes, its not the normals, the texture is on the outside where it is supposed to be.   However, not all of the texture is being applied where I mapped it.  I did find a couple of errors in the mesh (I don't think they explain all of the problem however and should not have caused what happened).  So all I know to do is go back to an earlier save, an begin rebuilding the mesh, then remap and try again.

What I am building is a sort of fantasy obelisk prop.  There is a pedestal base, an ornamental mid part and then an obelisk atop that.  The obelisk part maps and textures fine.  Most of the pedestal base does as well, except there are four flat faces on the side, there the texture seems to have oddly rotated and twisted.  Yet the UVMap is fine and all the vertices, edges and faces in the prop seem to be fine.  In blender the texture map applies correctly and renders fine.  But when I export it as an OBJ file, import into Poser 6, those same faces twist the texture (that is, its as though how the texture being applied to the face somehow got twisted or rotated and is not how it was UVMapped).  I cannot for the life of me figure out why.  Its very frustrating, this was going to be my next freebie prop but I can't release it til I get this sorted.

Meanwhile, I'm rebuilding the mesh and double checking everything to see if I can sort where it went wrong.

does your uv map look correct if you load the obj to uvmapper ? 

Check to make sure that SMOOTH POLYGONS is unchecked in your render settings. Sometimes this will mess things up in the render. If everything looks properly mapped in your preview window, that could be the culprit.

Well, I'm making progress.  I seem to have fixed my problem for now.  Went back to an earlier save, rebuilt part of the mesh and then completely remapped the UV from scratch.  Below is a test render with a simple checkerboard pattern I used to check for distortions.  It seems okay.

I still have no idea what caused the earlier problems.  I can only assume I must have hit a hotkey or something while working on the UVMap and done something without being aware of it that introduced problems into the map / mesh.

Anyway, with the problem apparently resolved I'll get back to finishing up the project.

On question, is there any notable difference between importing OBJ files in Poser 6 vs Poser Pro 2012?  I'm hoping to upgrade later this year.   Could it have been a flaw in Poser 6 that caused the problem?  I'm still puzzled since the original I made as well as the one above rendered fine in Blender, but the first mesh had problems when imported to Poser 6.

Thanks for the advice, always appreciated.

did you APPLY all modifiers?? (is a check box on export as a "failsafe")

I have had stuff look ok in blender then WTH in poser and its 'cos I had forgot to apply the sub-D

There weren't any modifiers on the mesh to apply in this case.  Besides, I don't see how not applying a modifier to the mesh (had I used them) would cause the UVMap to become twisted.  Wouldn't not applying modifiers and removing them from the stack (such as Mirror or Solidify) cause the exported mesh to itself be deformed or incomplete?  The mesh itself was not deformed, it imported to Poser exactly as I had created it in Blender.  That is, the shape was correct, the vertices were all where they should be and so forth.  The UVMap, in specific locations, simply wasn't being applied the way it had been mapped.  For example on the front of the base the texture was turned at what looked like about 30 degree CCW, and somewhat skewed, but the sides and back were fine.  The middle portion of the orb was fine, but the very top and bottom edge (cooresponding to the last rows of polygons) were inexplicably stretched and skewed.   Whatever the cause, as you can see from the render above they are all fine now.

I suspect that while I was unwrapping and editing the UVMap I must have hit a hot key such as F or something causing it to create connections in the mesh between vertices that shouldn't have been there and which I couldn't see an that may have produced the warping effect.  When I rebuilt the mesh from an earlier model (which didn't exhibit the problem), I was very careful about making sure I didn't do that accidentally, and things seem fine now. 

There was one other issue that was resolved by subdividing a few square facets into two triangles.  Poser seems to prefer triangular facets to square facets in some cases (if the square is stretched into a trapazoid for example).  Or at least, when I converted the problem facets to triangular ones the remaining distortion disappeared.

I will keep your note about modifiers in mind in the future.  I can imagine that could cause quite a lot of things to go wonky.