Obtaining Model Marker Trajectories

[Conrad Slater]

Hello all,

I'm relatively new to OpenSim and I have a question regarding the model marker trajectories. Is there a method to obtain/extract the xyz coordinates of the model markers over the course of a trial? Naturally I have the experimental trajectories in the .trc file which are used for Inverse Kinematics, however I would like to get the trajectories of the model itself following Inverse Kinematics.

Thank you!

[Thomas Uchida]

Is there a method to obtain/extract the xyz coordinates of the model markers over the course of a trial? Naturally I have the experimental trajectories in the .trc file which are used for Inverse Kinematics, however I would like to get the trajectories of the model itself following Inverse Kinematics.

You can open the IK Tool setup file (.xml) in a text editor and change the report_marker_locations property to true.

[Conrad Slater]

Great, thank you very much!

[Brecca Gaffney]

Tom,

Is there a reason that this file is not written when this setup file is called (with report_marker_locations set to true) using the InverseKinematicsTool from the Matlab API?

Thanks for your help.

[Thomas Uchida]

Is there a reason that this file is not written when this setup file is called (with report_marker_locations set to true) using the InverseKinematicsTool from the Matlab API?

Several possible explanations come to mind. Is the file generated when you run the Tool in the GUI using the same setup file? Also, I took a quick glance at the code and it looks like the file might be written to a different directory than the other results. Perhaps MATLAB doesn't have the necessary permissions to write to the target directory?