Finally, in a blow for free moddery everywhere, Cmo has released a Blender import/export script.
You can get it over on MTS - click on the link to go to the MTS thread.
Link to Blender plugin
What does it do????
1. Select the MLOD/MODL in s3pe, right click on it, and select "export". Rename the the file to name.lod(for MLODs) or name.model(for MODLs). Renaming is really only necessary for files with long names, because Blender has a limit. Save the file in it's own folder.
2. Open the MLOD/MODL file with the S3 Object Tool and decompile it.
3. Start Blender, and go to File->Import->Sims 3 MLOD/MODL. Navigate to the your folder and select the name_filebase.s3asc file.
To assign a new mesh to a group:
1. Right-click on the new mesh, the hold SHIFT and right-click on the mesh you want to replace.
2. Press TAB to o into Edit mode, Select all the vertices, and hit DELETE(X). Select "All" in the pop-up.
3. Press TAB to go back to Object mode, and press CTRL+J to join the new mesh to the group.
To assign vertices to the joints:
1. Right-click on the mesh and press TAB to go into Edit mode.
2. Select the vertices you want to add to a joint. In the Properties editor, select the "Object Data" panel(button with triangle/w dots at the corners).
3.In the "Object Data" panel under 'Vertex Groups', select the joint you want to assign to, and click assign.
Note: Make sure to triangulate all meshes before exporting. Select all vertices in Edit mode and press CTRL+T.
1. Go to File->Export->Sims 3 MLOD/MODL. Navigate to the folder you imported from, select the name_filebase.s3asc file, and press "Export MLOD/MODL".
2. Recompile the MLOD/MODL with the S3 Object Tool.
3. In s3pe, open the package. If you didn't rename the file when you exported it from s3pe, right-click and select 'Import'. If you did rename the file, right click on the MLOD/MODL and select 'Replace'.
Testers are wanted.