Model will not apply any saved changes

[Nathan Thompson]

Hello All,

I'm having a strange issue trying to manipulate a model. I'm working with the Lai et al., 2017 full body human model (https://simtk.org/projects/model-high-flex). The issue I'm running into, is that whenever I try to change something in the model and save it, the save never applies. For instance, if I open the model and add markers to the model (which works), but then save the model, when I re-open it the markers have disappeared. Moreover, if I add markers, save them to an .xml, save the model, reopen the model, and then try to load that .xml file, it wont apply any markers to the model, despite receiving a message "Updated model markers in ...". This is the first time I've experienced this, and its only the models specific to this project; other project models save/update just fine. I've checked to make sure I'm running as administrator in case its a permissions issue, and that hasn't worked. I've also double checked that the files are not 'read only' and they are not. It's also happened in both OpenSim 4.1 and 4.0. The only thing I can think of is that the model was created in OpenSim 3.3 (I think), though even then I have other models that are as well and this doesn't seem to be an issue.

Can anyone think of a reason why this might be happening or how to fix it?

Cheers,

Nathan

[Ayman Habib]

Thanks for reporting, Nathan.

I was able to reproduce the issue and opened an issue on github to track here
https://github.com/opensim-org/opensim-gui/issues/1266

Will update the issue as we find more info and/or workarounds.

Best regards,
-Ayman

[Ayman Habib]

Hello Nathan,

Investigating this issue, it turns out that the syntax of the .osim file is the issue. Removing the empty <MarkerSet> element completely solves the problem, same correct behavior can be achieved with adding the missing </objects> tag within the <MarkerSet> in the latest format.

Since the model has reported issues with coordinate/motion types in 4.0+ stream, I suggest you contact the model developers to fix both issues and publish an updated version.

All the best,
-Ayman