Model registration from fiducial point

Hello everyone,

I’ve overlapped a preoperative femur and postoperative femur, where the femoral head position was changed. I’ve overlapped them using ALPACA to measure the rotations and translations.
before
image

Now i managed to use the “rotate a node around a specified point” script to be able to rotate the head from a point relative to its shaft, so we have a singular point to measure from with other patients.

However, i can not figure out how to measure the ALPACA overlap from this new point, is there a way to do this.

Thank you in advance.