How do I create an output to measure the absolute angular displacement of a ball joint entity in MotionView?

Joseph LaCola

GTT Adam

*This case was answered internally, but is being reposted for the community:

Hi Joseph,

There are multiple ways to measure the angular displacement of a ball joint:

1. You can measure the rotational displacement of joints by creating an Output  Link to Help. Configure the Output to measure the displacement of an entity, which you can filter then to joints, and then pick the ball joint. It will record the angular displacement of the joint from this initialized position.
2. If the initial angle of the joint is required, then you can create an Output using Expressions as well.
   1. Create a marker on each body used for the joint and is located at that joint.
   2. Make sure that the markers have 1 coincident axis (Z shown in picture).
   3. Align a second axis (Y shown in picture) along each cylinder (in this case).
   4. For your Output Expression, use the RTOD (radians to degrees) and AZ (measure angle about the z axis) commands like so:
      1. `RTOD(AZ({marker_1.id},{marker_2.id}))`

Thanks,

Adam Reid

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