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Hi all,

I am trying to implement a head3dir.mot file for the 6dof model from Vasavada. I assume this is somewhat similar to teh head3dir.mot file for the 3dof model she has already lain out. However, I encounter problems in implementation. I have set my columns as pitch1, pitch2, yaw1, yaw2, roll1, roll2, respectively (where it runs the pitch, then the yaw, then the roll). When I do this, the pitch runs through the entire course, and in the last few steps, the latter half of the roll data runs through in large incremental steps. I do not know where the yaw motion goes, or how this is running its action. Anything would help!

Thanks,
Travis

Hi Travis,

You can load the model in the GUI to see if your model behaves correctly when you move the coordinate sliders and then set the values in the motion file accordingly. The values for rotational degrees of freedom in a motion file are specified in degrees.
Hope that helps,
-Ayman

Hello,

I am trying to rewrite .mot files to input into my model. Is there a special compiler or program needed to write these .mot files? Or are there any sort of formats for the data (filename.mot in .txt format, etc?) I have tried inputting Rows and Columns of text in Excel and then saving the data in Wordpad, however these do not seem to be able run in OpenSim.

Thank you,
Travis

Yeah, editing them in Excel unfortunately doesn't work very well. You can try Tim Dorn's c3d extraction toolbox for matlab (which is how I get my mocap data in trc files). It has a a function generateMotFile.m which can be used to make a .mot file from a data matrix (doesn't have to be from a c3d file).

https://simtk.org/home/c3dtoolbox

Hi Travis,

They're normal text files (I usually save in tab delimited directly from Excel). The catch is that the header must be done exactly right; 9/10 times when one doesn't work for me I've put an extra space in the header or something.

If you shoot me an email at daniel dot leib at gmail dot com I'll send you an Excel file that saves into a successful mot file so you can see how the header has to be set up.

-Dan

Hi Travis,
if you are familiar with Matlab, I suggest you to use Matlab package developed at Stanford and available at:

https://simtk.org/project/xml/downloads ... kage_id512

You can read C3D files without using C3Dserver!
It will take you some time to get familiar with all the functions, and maybe to do slight corrections to the code.

Davide