Global Position

Hello everyone,

I'm currently working with AnyBody to run simulations in order to generate data for later attempts at predicting the position of the Pelvis in a seated posture. I'm quite new to AnyBody, and I’ve encountered my first question.

I need to extract the positions of the following anatomical points:

  • LASIS
  • RASIS
  • LPSIS
  • RPSIS
  • C7

For each of these points, I can see both r and Axes values in the output .h5 files. From what I observe, the values in r do not appear to be in global coordinates.
However, my goal is to compute the equations of planes formed by subsets of these points for further data processing and analysis — so I need their positions in the global coordinate system.

Could someone please help me understand:

  • How exactly can I compute the global coordinates of these points using the data available?
  • Are r and Axes sufficient for this transformation?
  • Also, does the Axes matrix store its coordinate axes as rows or columns?
  • Is it correct to obtain global coordinates by simply multiplying the Axes matrix by the r vector?

Thank you in advance for your help!

Hi Mikhail,

Welcome to the AnyScript Forum!

I can assure you that r and Axes for any reference frame are in global coordinates. These are system outputs, so there is no possibility of accidental manipulation either.

Can you visualize the global reference frame in your model and check again?

Best regards,
Dave