Rotating Force Plates

Dear Michael,

Hello There,

In the new GaitLowerExtremity model how do I rotate marker and forceplate data into the GlobalRefFrame. I like the class_templates that handle Marker and Force Plate data, they’re a great addition, but I can’t seem to add an AnyMat33 to either to influence the orientation of our MOCAP data. We can output C3Ds of our kinematic data in different orientations to match the AnyBody GlobalRef but there is no option to do this for the kinetic data.

Is there a quick and easy way to rotate the force plates?
Altering the AnyRefFixedFrame “GlobalRef” in Environment.any doesn’t seem to do the trick.

Best regards,


Hey Stephen!

The way to rotate the force plate is to rotate the reference frame, which is used to control the orientation of the force plate segment in the enviroment.

As I do not have the model here right now, I cannot tell you exactly where to find this reference frame, but if you start off by locating the force plate segment then look for an AnyKinRotational, which is driven to zero.

I hope this helps.

Best regards
Michael Skipper Andersen
The AnyBody Research Project

Hi Stephen

The forceplate classes make use of the c3d file to detect the corners of the plates, normally these corner coordinates comes from markers place on the plates, so this should take care of rotating the plates into the right orientation.

So if it all works, it should go automatically and the only thing you will need to change is the gravity vector to make it match the global ref of your lab

If you want to alter the forceplate orientation in the class then it is the
PlateCenter.ARel you will need to change i think.

Best regards