Simbody is open source; the code can be found on GitHub here: https://github.com/simbody/simbody . I presume the calculation you would be interested in is HuntCrossleyForceImpl::calcForce() , which is here: https://github.com/simbody/simbody/blob/master/Simbody/src/HuntCrossleyForce.cpp#L101 . If th...

Some information can be found in the Simbody Theory Manual ( https://github.com/simbody/simbody/blob/master/Simbody/doc/SimbodyTheoryManual.pdf ). See, in particular, Sections 11.1 ("General Force Subsystem") and 11.2 ("Hertz/Hunt and Crossley contact model subsystem"). The following paper contains ...

It's difficult to diagnose the issue without more information about how to reproduce the error. If you are attempting to add body segments by modifying an existing osim file manually (e.g., in Notepad++), then there may be an error in one or more of the Socket paths. If you are attempting to add bod...

Descriptions of a model's coordinates can typically be found in a publication (see the "publications" tag at the top of the osim file). Information about some popular models can be found on the "Musculoskeletal Models" page in the documentation ( https://simtk-confluence.stanford.edu:8443/display/Op...

You might want to take a look at some papers that have done this already (e.g., search Google Scholar for "OpenSim ligament"). Some of these models have been uploaded to this website (e.g., https://simtk.org/projects/kneeligament) which you could use as a starting point.

Initially it gives an error (check below image). The message in the "Warning" window is just a warning. Please see the "Upgrade Notes for OpenSim 4.0" page in the documentation for more information about this message (specifically, see the information about updating joint types in the "Upgrading yo...

An example can be found in testActuators.cpp (see the testBodyActuator() method here: https://github.com/opensim-org/opensim- ... s.cpp#L546). The BodyActuator is created and configured starting at line 648.

Please see the "Common Scripting Commands" page in the documentation ( https://simtk-confluence.stanford.edu:8443/display/OpenSim/Common+Scripting+Commands ) and search for the string "downcast". In your case, the code will be something like the following: spring = PathSpring.safeDownCast( model.get...

Hello -
Apologies for the delay. Scripts are coming soon.
Best wishes.

You could try the following: 1. Find the coordinates of the marker (x,y,z) with respect to the segment coordinate system. 2. Set z=0. 3. Express the new marker location with respect to Ground. If you're using the API, you can use the Frame class to perform steps 1 and 3; see Frame::findStationLocati...