Duplicate Vertices on OBJ Export

 From:  Michael Gibson
4424.3 In reply to 4424.1 
Hi Skwerm - like Burr mentions that's your choice for there to be duplicate vertices or not depending on whether you set the "Weld vertices along edges" option when exporting from MoI.

That option is on the meshing options dialog here (expand it to get the full controls if you've currently got the compact version of the dialog):




For example if you export a cube object with welding enabled, there will only be 8 3d point vertices in the resulting mesh and the different faces of the cube will share some points in common with one another.

If you export with welding disabled, then each surface will have its own separate vertices along where they shared edges, with the vertices stacked up on top of each other.

That's an option because for some kinds of uses you may not want to have welding - if you plan on separating all the faces from each surface into different objects in your polygon modeling program that may be a bit easier to do with unwelded output since the pieces are not topologically connected. Also some kinds of special effects like outlines on some toon style renderers may rely on having non-shared edges in the mesh to know where to place their outline lines.

Also occasionally some programs may have difficulty with importing files that are welded, where 2 polygons share a single point in common but have distinct UV and vertex normals for each face that use that same 3d vertex point.

But if you don't want to have duplicated vertices in your export, just check that option and you'll have a single shared vertex in those areas instead of duplicated ones.

- Michael