Why can't I load my OpenSim model into the mesh importer?

[adamkewley]

AK: This question was ported from akewley@tudelft.nl . Some details were REDACTED or edited because the original question was private.

I was able to create the whole rotationplasty geometry that I need, meshes and joints. As there are to be two different muscle models I saved this bones-only version as an .osim with the intention of then adding one set of muscles to the base and then a second set of muscles to the same base. Problem is that I now cannot get my model back into the mesh editor to add my muscles. Is this workflow not possible? No way to import the .osim into the mesh editor?

[adamkewley]

No, you can't use the mesh importer to build your model beyond basic mesh + bodies + joints + stations placement. The reason why is because the mesh importer is an entirely separate UI that uses an OSC-specific datastructure (this is why the mesh importer feels more free-form etc. - it's built from the ground-up in OSC).

Once you have an osim file and you start to add anything beyond those basics (e.g. muscles) then the mesh importer will not be so helpful, and you'll have to continue future development in the OpenSim model editor (i.e. the main editor), because that editor is designed to be 100 % compatible with all of OpenSim's idioms etc.

Frustrating, I know, but it's because I had a UX goal for initial model prototyping and didn't want to play the OpenSim game to achieve it, so the mesh importer ended up being somewhat developed on an island, which is why most recent development has been focused on adding similar nice-to-haves into the OpenSim model editor UI