Plotting motions at other points on the vessel

The Pitch and Heave that are reported during a standard Orca3D Marine CFD simulation are at the center of gravity, or at the tow point if the tow point is moved away from the center of gravity. If you want to see the heave at other locations, this can be done by creating custom plot variables. The SimericsMP expression editor allows you to define custom plot variables that you can use to show time histories of any derived quantities that you want. In this case, those quantities are the heave values at the bow and transom. So inside the expression editor you would define expressions as shown below. 

For your model you would set the xAtBow, xAtTowPt, and xAtStern values accordingly for your model. Also watch the signs as marine.pitch is negative for bow up regardless of Y axis of your model (it uses in internal port axis for defining positive pitch), and the xAt... values depend on the direction of X in your model. Also the model in SimericsMP is in SI units even if your Rhino model is not.

To plot the heave at bow and stern, open a new XY plot and select the "Common" module in the Model panel. Any user-defined plot variables should now show up in the list of available variables as shown further below.

Note that this analysis is valid for the simple case of surge, pitch, and heave dynamics only. The relationship between motion at the CG and motion at a point become more complex for full 6-DOF motions.