• FAQ

FAQ

If you ran into the same question over and over, probably other users did as well. Please add yours to the end of the list below:

• When to use the class OpenSim::SimbodyEngine? The class SimbodyEngine represents the Dynamics Engine inteface. It offers functionality similar to how SDFast worked (methods to query the State object and recover kinematic and dynamic info, apply forces, compute reactions, ...etc.). Methods of the SimbodyEngine usually require a SimTK::State argument.

• How do I get reference to parts of the model (Bodies, Forces, Muscles, Controllers, ...)

  1. If you need only a const ref (not modifying anything) use one of the "Model" class methods model.getBodySet().get("BodyName"); // use ForceSet for all forces/muscles, ..

  2. If you need a "modifiable" reference use model.updBodySet().get("BodyName");

• When do I call the method model.initSystem()? The call to initSystem must occur after all model construction is done. If you need to modify the model after that you need to call to call initSystem() again to get a new SimTK::State.