I am returning to using opensim and I'm relearning a lot of stuff. I'm running into a problem however with getting my data prepared for opensim. I have a c3d file from a motion capture trial done with VICON. I am trying to turn that c3d file into a .mot and then load it onto a full body model. I'm have the following issues:
1) Not sure what full body model to use. I'd like to have the full bodies musculature but right now the only read to go full body model I can find is just the lower body Currently I am using the Fullbodymodel4.0 by rajagopal 2015
2) When loading my motion I get a "can not associate motion with model" error
3) I'm trying to do ground reaction force prediction so I don't have a grf.xml file
4) I'm not sure how to prepare the c3d file. I loaded it into opensim mokka, used the gait event tool to label right and left foot heel strike and toe off. I then exported the modified c3d and then used c3dtools.com to convert from c3d to .mot. However I still get the "can not associate motion with model" error
I've been at this for a few days now and can't make heads or tails of how to get everything prepared. Can someone help me?
Below are links to my files:
https://drive.google.com/file/d/1XlmlFx ... sp=sharing
https://drive.google.com/file/d/11_1nPl ... sp=sharing
NEED HELP WITH DATA PREP
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Christopher Hollhumer
- Posts: 3
- Joined: Wed Feb 09, 2022 8:07 am
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Jon Stingel
- Posts: 17
- Joined: Fri Jan 19, 2018 5:54 pm
Re: NEED HELP WITH DATA PREP
Hi Christopher,
Here are a couple of thoughts based on your description:
1) This could depend on your project goals. There are a number of different .osim models that the research community has tested and used. You can check many of the out on the following page, and feel free to mix and match models to meet your specific needs. Depending on what muscles, degrees of freedom, etc. you might find one that meets your needs.
https://opensimconfluence.atlassian.net ... tal+Models
2) What data is in the file that you are trying to associate with the model? Motion and force data? and what type of motion data (eg. motion capture, etc.)? The "Load motion" option in the GUI is typically for loading in .mot or .sto files that contain joint coordinate data that can be used to describe the motion of the model, and so you would likely need to convert your data to one of those formats.
3/4) For handling your C3D files, there could be a couple options, including other software packages. If you are comfortable with scripting, you can check out the documentation page for processing these files and see if any of the methods listed would fit into your pipeline. Alternatively, you could check out AddBiomechanics, which also handles C3D files and automates the scaling and inverse pipeline.
https://opensimconfluence.atlassian.net ... .c3d+Files
https://addbiomechanics.org/
Hope this helps!
Jon
Here are a couple of thoughts based on your description:
1) This could depend on your project goals. There are a number of different .osim models that the research community has tested and used. You can check many of the out on the following page, and feel free to mix and match models to meet your specific needs. Depending on what muscles, degrees of freedom, etc. you might find one that meets your needs.
https://opensimconfluence.atlassian.net ... tal+Models
2) What data is in the file that you are trying to associate with the model? Motion and force data? and what type of motion data (eg. motion capture, etc.)? The "Load motion" option in the GUI is typically for loading in .mot or .sto files that contain joint coordinate data that can be used to describe the motion of the model, and so you would likely need to convert your data to one of those formats.
3/4) For handling your C3D files, there could be a couple options, including other software packages. If you are comfortable with scripting, you can check out the documentation page for processing these files and see if any of the methods listed would fit into your pipeline. Alternatively, you could check out AddBiomechanics, which also handles C3D files and automates the scaling and inverse pipeline.
https://opensimconfluence.atlassian.net ... .c3d+Files
https://addbiomechanics.org/
Hope this helps!
Jon