Hello Ayman, Thanks for the analysis and answers you gave. Actually, I got the marker position by optitrack acquisition and then solved the individual joint angles inversely by modeling the upper limb. But as I said before, in some cases, after the inverse solution is finished, an entry of the inver...

I can see the red cross in the right below of the messages window. A java.lang.ArithmeticException exception has occurred. Detailed error message: java.lang.ArithmeticException: / by zero at org.opensim.threejs.ModelVisualizationJson.calculateWrapPointsToVisualzerPointsMapping(ModelVisualizationJson...

Helle, everyone! I'm having problems using the MobL_ARMS_unimanual model in Upper Extremity Dynamic Model. I have changed the osim file of the model (including range limits and marker point locations). In some cases this works, but in some cases, after I successfully run the inverse kinematics tool,...

Thank you so much Aaron,

I've noticed the '_ik_marker_errors.sto' file in directory of my python file. I used to think it will appear in the folder of my model. By following your way, I've succeeded in recording the errors output.

Hongyuan

I am trying to using the python and opensim4.5 to do the IK with python. The following sentences is written: import opensim as osim model = osim.Model('mypath/model.osim') state = model.initSystem() ik_tool = osim.InverseKinematicsTool() ik_tool.setModel(model) ik_tool.setMarkerDataFileName(trc_file...

Thank you very much for your response. As a first-time user of the OpenSim API, I'm not yet clear on all the differences. I tried what you suggested, and it turns out that setValue only changes the current state, having no effect in the InverseKinematicsTool(). However, using set_default_value() and...

I attempted to use the Python API to achieve the functionality of locking certain values in the Coordinates section within OpenSim. The overall code is shown below. In Python, I first perform IK on the first 50 data points to obtain the mean values, then I lock the trunk coordinates (such as 'r_x', ...

Hello, I am new to OpenSim and SimTK and I am trying to use upper extremity dynamic model to simulate human movements and get two matrixes ( Jacobian J and muscle Jacobian Jm). The Jacobian is a matrix of partial derivates that relates small end-effector (hand) velocity V with small joint angle chan...