[BUG] Move Markers on a JMPBody Moves Different Markers by Different Amounts

[bfregly]

Describe the bug Run JMP with settings file that 1) Makes torsue a JMPBody and scale torso, and 2) Makes pelvis a JMPBody and allow pelvis markers to move in Y direction. 3) Sets to true so that torso markers scale with torso.

JMP'ed model has R_ASIS and L_ASIS markers moved upward by different amounts.

Both ASIS markers + Sacral marker should all move upward by the same amount in the pelvis body.

To Reproduce Steps to reproduce the behavior: Run the attached JMP settings file JMPScaleModelMoveMarkers_b.xml.

Expected behavior All pelvis markers should have moved upward or downward in the pelvis by the same amount.

Screenshots If applicable, add screenshots to help explain your problem.

I think JMP may be moving all pelvis markers by the same amount - just not in the same positive or negative direction.

Desktop (please complete the following information):

• OS: Windpws Bug1.zip

  

• OpenSim Version: 4.5

• MATLAB Version: 2023a

• NMSM Pipeline Version: v1.1

Additional context Add any other context about the problem here.

[cvhammond]

When body scaling and marker motion were added to JMP it was determined in an NIH team meeting that each marker should move independently because the purpose of the marker motion was to absorb small errors between the static trial used in the OpenSim GUI Scale Tool and the gait/joint trial used for JMP.

Marker motion with JMP was not designed for a use case where all markers needed to be moved as a group because the model is supposed to be scaled properly before coming to JMP. Marker motion is for small marker-specific movements.