How do I add a PrescribedController to a model?

[adamkewley]

AK: This question was ported from akewley@tudelft.nl . Some details were REDACTED or edited because the original question was private.

Students faced an issue today in class when trying to add a PrescribedController that controls a PointToPoint actuator via OpenSim Creator. Do you think that they are doing something wrong? (I attach the model that they are using and the .sto file in which the control values for the controller should be stored).

[adamkewley]

The error is because OpenSim's Controller API requires entries in the actuator_list to be the names, not paths, of actuators in the model.

The fix is either:

• Leave actuator_list blank, which will cause the implementation to figure out what the actuator is from your STO file (i.e. it will automatically populate PointToPointActuator in the actuator_list field)
• Or write "PointToPointActuator" in the actuator_list field (i.e. just the name of the actuator)

Relevant source code in OpenSim: https://github.com/opensim-org/opensim-core/blob/4.5/OpenSim/Simulation/Control/Controller.cpp#L177