Hi Christian and Aaron, Aaron is correct -- FunctionBasedPath s do not support a method for visualization in OpenSim currently. FunctionBasedPath s compute muscle lengths, velocities, and moment arms directly from user-provided functions. In that sense, there is no longer any physical geometry that ...

Note that there may currently be a bug related to installing OpenSim with Matlab 2024b: https://github.com/opensim-org/opensim-core/issues/3958.

Hi Herman, Filtering is applied after the kinematics step (e.g., marker fitting) to smooth joint kinematics before dynamics fitting, but we do not apply any filters to the input data. Whether or not you filter the input data, it is most important that the input marker data is "clean" (i.e., no frame...

Hi Yiming,

What type of processor does your Macbook have? Is it an Intel-based processor (x86_64) or an M1/M2/M3 (Arm64) processor?

Have you tried installing OpenSim on an older version of Matlab?

Best,
Nick

Hi Filip, Thank you for your post. I have one brief suggestion, which is that you might find the class ExpressionBasedBushingForce useful for modeling vertebral passive forces. It will allow you to define passive 3D force and torque expressions that are a function the relative orientation and displa...

Hi Lucinda, Could you provide more details about your installation process? It sounds like you may have either 1) installed the base OpenSim distribution instead of the OpenSim JAM package or 2) you installed OpenSim JAM but you have not updated your PATH variable correctly to point to the OpenSim J...

Hi Pasha, I'd say this is more of a design limitation of MocoTrack, rather than a bug. By default, MocoTrack sets the initial guess based on explicit dynamics mode. If you switch to implicit dynamics mode, the default guess set by MocoTrack will be incompatible with the problem, which is why you nee...

Hi Maria, I see. Yes, unfortunately we do not have a method similar to addNewPathPoint for MovingPathPoints in Muscle. However, since you've already constructed the MovingPathPoint yourself, you should be able to add it to the model by updating the muscle path's PathPointSet : pathPointSet = Latissi...

Hi Maria,

If you could provide a minimum working example that reproduces the errors that you are encountering, along with the error messages, then we can assist with debugging your issue.

Best,
Nick

Hi Sakamo,

That error usually occurs when the optimizer struggles with the problem initial guess. Are you using the default initial guess or providing your own? Some general details about your problem would be helpful too.

Best,
Nick