Mesh import and re-export

Hi

I need to put together a model for 3D printing which will comprise a single water tight textured mesh. Because of the size of the model I need the texture broken down into a number of separate UDIM's.

To do try to achieve this I have exported an initial mesh from RC, cleaned up the mesh in Design X and Mesh Mixer and then re-imported the model back into RC for re-texturing. However, when I then export the textured model back out of RC it is exported as a group of 34 meshes and it looks like RC beaks the model down into a separate mesh for each separate UDIM.

This causes problems when I then try to edit the texture maps and when I try to further process the model to get it ready for 3D printing.

I need to be able to export the Obj model as a single mesh with one single texture set containing all the different UDIMs ( as opposed to a group of meshes with each mesh having its own texture set containing one UDIM).

Is this something I can achieve ? - if so how ?

Kind regards

Robert Ward-Booth