Blender OBJ vs 3DS OBJ and manifold mesh

[lex3001]

When I load a manifold mesh that was exported from 3DS everything is as expected. When I load the same mesh exported from Blender, the loaded mesh is no longer manifold. It seems to be missing how the triangles are connected. Maybe I am using an older version of geomtry3Sharp - is this a known issue (I did a few searches here but was not able to find any details)? Has it been resolved? Any idea what could be causing it and how I might fix it (other than exporting everything from 3DS)?
Thanks in advance.

[rms80]

If the mesh comes in disconnected, then this is probably how it was exported from Blender, the OBJ reader is just doing what the OBJ file tells it to do, ie it doesn't explicitly weld anything itself.

You could try importing the same OBJ meshes into, say, Autodesk Meshmixer (meshmixer.com) and see if you have the same problem. If so then it's the OBJ file itself.

Possibly Blender OBJ export has options that control this behavior.