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How to pass CSV or C3D Nexus Data to OpenSim

Posted: Sun May 28, 2023 2:17 pm
by christian9876
Hello everyone,

I am currently processing some experimental data from climbing motions. This data was taken using nexus with vicon cameras. I got CSV and C3D files with markers properly labelled but I do not have force plate data as the movements were directly taken during the climbing motion. Is it possible to pass this data in C3D and CSV to an usable format to evaluate the results and movements on OpenSim? I have seen a few toolkits but all of them seem to require force plate data. If I don't have force plate data is it impossible to analyze with OpenSim?

Thanks

Re: How to pass CSV or C3D Nexus Data to OpenSim

Posted: Mon May 29, 2023 6:21 pm
by aafox
Hi Christian,

Newer versions of Nexus (post v2.x I think) have an option to export marker data in a TRC format - which is the format used in OpenSim (I believe the export process even re-orients the data to the OpenSim coordinate system standard). You could then use this TRC data in inverse kinematics - but without force data you wouldn't be able to use any of the dynamics related tools (e.g. inverse dynamics, RRA).

Aaron

Re: How to pass CSV or C3D Nexus Data to OpenSim

Posted: Tue May 30, 2023 12:01 pm
by aymanh
Thanks Aaron,

I'd just add that our C3D reader can extract marker data as well, the process is documented here
https://simtk-confluence.stanford.edu/d ... d%29+Files

Hope this helps,
-Ayman

Re: How to pass CSV or C3D Nexus Data to OpenSim

Posted: Mon Jun 05, 2023 3:00 pm
by kernalnet
Hi, markers data in C3D can be easily exported to TRC using MOKKA. Also, several tools are listed here: https://simtk-confluence.stanford.edu:8 ... otion+Data
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