Mokka 0.4 is available for free download

[Stephane Armand]

Mokka 0.4 is now available for free download for Windows and MacOS X, both for 32-bit and 64-bit architectures: http://b-tk.googlecode.com/svn/web/mokka/index.html

Mokka (Motion Kinematics & Kinetics Analyzer) is an open-source and cross-platform software to give you the possibility to explore your biomechanical data in several ways and directly from the files saved by your motion capture system (C3D, TRB, TRC, ANB, ANC, RIC, EMG, ANG, MOM, ...).

This new version introduces mainly the possibility to plot all of the data embedded in an acquisition file. So you can now easily visualize the motion in 3D views and see the corresponding value for EMG, force platform, joint angles, etc. in 2D charts.

Check the documentation provided with Mokka or browse it online to see all of the possibilities of the software: http://b-tk.googlecode.com/svn/doc/Mokka/0.4/index.html

The goal of this project is to focus on the interoperability of the file formats obtained by different acquisition systems and to give you the possibility to display their content easily.

For more informations, you can contact us by using:
- the forum: http://groups.google.com/group/btk-users
- twitter: http://twitter.com/btkwww

Best regards

Stephane ARMAND
On the behalf of BTK/Mokka group
Willy Taillard Laboratory of Kinesiology
University Hospitals of Geneva

[Drew Smith]

Re: Mokka 0.4 is available for free download

Stephane,

I really like this package (at first glance - need to give it a more close inspection). However, I notice that it is not possible to import or open .tdf files, which I believe are the file format used by BTS Smart-D systems (such as ours).

Are there any plans to add this functionality to the program in the near future?

[Edmund Cramp]

Re: Mokka 0.4 is available for free download

Hi Drew,

The BTS SMARTanalyser software supports the C3D file format so just export your data to a C3D file and open in in Mokka. This should work for any motion capture software that supports the C3D standard.

[Drew Smith]

Re: Mokka 0.4 is available for free download

Hi Edmund,

The interesting thing about the BTS C3D export is that their force platform data are Type 1 force platforms (I think I got that right) and as I understand it, most systems expect type 3 (or have I got that back to front?). I learned this when I tried to open a BTS-exported C3D file in both Vicon Workstation and Motion Monitor. We had marker data but no forces. MM helped us with a work-around.

[Arnaud Barré]

Re: Mokka 0.4 is available for free download

Dear Drew,

The addition of the TDF file format is planned and we have already someone working on it. I hope this format will be added in the next release.

Thanks for your interest to Mokka.

Don't hesitate to send us a mail if you have any question or suggestion,

Regards,

Arnaud

[Drew Smith]

Re: Mokka 0.4 is available for free download

Arnaud,

That's great news. Please keep us posted.

Thank you!

[Edmund Cramp]

Re: Mokka 0.4 is available for free download

The interesting thing about the BTS C3D export is that their force platform data are Type 1 force platforms ...

Yes, I found that out independently this weekend too (synchronicity at work?). To the best of my knowledge Vicon software supports most force plates derived from TYPE-2 and TYPE-3 plates but has never supported TYPE-1 plate data.

In the BTS generated C3D file that I've seen the data is either computed from raw force-plate data that was not exported to the C3D file, or else the ORIGIN parameter (the displacement from the force plate coordinate system origin to the working surface of the force platform) stored in the C3D files is incorrect - it's zero.

From a customer support point of view, I much prefer to see C3D files that contain raw force-plate data as it makes it possible to check for, and correct, problems with the force plates. When the force plate data is calculated you just have to hope that it's correct.

[Drew Smith]

Re: Mokka 0.4 is available for free download

... From a customer support point of view, I much prefer to see C3D files that contain raw force-plate data as it makes it possible to check for, and correct, problems with the force plates. When the force plate data is calculated you just have to hope that it's correct.

I can't agree with you more. What I do like about VICON is that your force platform data is 'uncorrupted' by whatever mucking around you may do. If you make a mistake, you can just reconstruct your data (also works if you change some of the amplifier settings etc.). Other systems (like BTS) do not allow this flexibility - if you save it in any modified form, the original data is gone forever.