How many forceplates can be set in AnyBody

Hello, everyone.
Could you tell me how many forceplate can be set at most in MoCapModel.
After 42 forceplate have been added into the c3d file which is then called by AnyBody, the model tree can’t be coustructed in the loading step.
Why there is a limit of the number of the forceplate to set? And how to solve the problem if I want to add more forceplates in it?
Another question is that, the directions of the forces and moments are in the global coordinate system or the local one?

Looking forward to your reply.Thank you very much!

Jing

Hello Jing

This sounds like a memory issue on your computer. Properly because your c3d file is containing a lot of data.

What is the size of the file?
How many frames is in your files
What is your “NoAnalogSamplesPer3DFrame” ratio between marker frame rate and force plate frame rate?

Check out this linkto find out more about the c3d file format.

If you can share the file with us, we can try to help you out.

The ground reaction forces are in the local ref frame of the forceplate.

Best regards,
Kasper Pihl Rasmussen

Hi Kasper,
Thanks so much for your quick reply. :slight_smile:

The size of my .c3d file is 129k.
10 frames are set in the .c3d file.
The ratio between marker frame rate and force plate frame rate is 1/10.

One thing has to be mentioned is that I rewrite the c3d file (got from vicon) by using the btk toolbox in Matlab. That’s because only marker’s traces were recorded in the former one, as I didn’t use the normal forceplates. I think the c3d file should be ok, because it can be loaded seccessfully with less forceplates in it.

Probably the reason is the memory issue of my computer, so I’ll try to load the file on a powerful one. Hope the problem can be solved then. I’ll share the outcome with you then.

Thanks a lot, Kasper.

Kind regards,
Jing

Hi Kasper,

I’ve tried to load the model on a more powerful computer, but unfortunately it still failed. The model tree couldn’t be constructed and the system crashed.

Attanched are the two files. The one named ‘ForcePlatfomSimplifiedCylinders’-‘MoCap_FullBody.main.any’ can be loaded and calculated successfully. While the other named ‘ForceplatformAllCylinders.zip’-‘MoCap_FullBody.main.any’ couldn’t be run. While the only difference of the two files is the number of forceplates in the c3d files.

Could you check the file and find a solution to the problem? Thank you very much!

Best regards.
Jing

Hi Jing,

Sorry for the slow reply.

It looks like there is an issue with reading this file you are right, we will try to debug this internally and see if the issue is in AMS or if it is “improper” values in the C3D.

I am not sure if you already found a workaround on this, but I suggest maybe to try to split the C3D file into two files and load both files… this might help you move on.

Best regards
Søren

Hi Søren,
Thanks SO much for your kind reply!

I’ve tried to split the c3d file into two, but there is something wrong with the force platforms names. Because I append the force platforms in Matlab, they are named as ‘#1’ ‘#2’ and so on in both of the c3d files.

That is in the two c3d files two force platforms are named as the same. While this can make confuse when loading the files in AnyBody with ‘’#include …/Input/ForcePlates.any/PlateName = Forceplatform1’’. Now I haven’t found the way to solve this problem with Matlab when naming the force platforms.

So I hope you can find the reason why AnyBody can’t loaded to many force plates, and get the solution.
Looking forward to good news.

Thank you again!

Best regards
Jing

Hi Jing,

This problem have been resolved, i will send you a private message shortly.

Best regards
Søren