To confirm that OpenSim works at all, you could try just creating a new model ("Model osimModel;"). If that works, the issue may be that Arm26.osim is in the wrong directory; you could try including the full path or copying the file into the directory containing the executable. Using a try/catch blo...

OpenSim isn't designed for editing meshes; there are other tools for doing that (e.g., MeshLab, ParaView). OpenSim Creator's Mesh Warper (https://docs.opensimcreator.com/manual/ ... /tut5.html) might be of interest as well.

This forum is for OpenSim (https://opensim.stanford.edu/). I think you're looking for OpenSimulator (http://opensimulator.org/wiki/Main_Page); it looks like they have a support page here: http://opensimulator.org/wiki/Support.

The implementation for loading mesh files can be found in Simbody (PolygonalMesh.cpp L242: https://github.com/simbody/simbody/blob/f16651cbf52695442159202099971b4fc4f5d3bd/SimTKcommon/Geometry/src/PolygonalMesh.cpp#L242 ). The doxygen can be found here: https://simtk.org/api_docs/simbody/3.5/classSi...

The muscles or residual/reserve actuators may be too weak, or there might be noise in the data. Please see the "Troubleshooting" section of the "Getting Started with Static Optimization" page in the documentation for some possible solutions: https://opensimconfluence.atlassian.net/wiki/spaces/OpenSi...

You can type "installResources()" at the prompt in the ScriptingShell window. If the ScriptingShell window is not already displayed, please see the instructions and images here: https://opensimconfluence.atlassian.net ... in+the+GUI.

Perhaps try using the Scale Tool (https://opensimconfluence.atlassian.net ... Scale+Tool) with "manual scales" of 10. The Scale Tool will take care of scaling joint locations, muscle paths, etc.

How are the ground reaction forces being included in the simulation? It sounds like they were not measured and are not being provided.

Are there any constraints in the model? If so, you should use coord.setValue(state, coord_value, False) and then call the assembler after the loop. Please see the comments in the documentation for the Coordinate::setValue() method here: https://simtk.org/api_docs/opensim/api_docs/classOpenSim_1_1Coo...

A quick way to remove components from a model is to edit the osim file in Notepad++. Alternatively, you may wish to explore OpenSim Creator (https://www.opensimcreator.com/).