[SOLVED] Update an engine at every step

Hello,

I’m trying to create a component that at each frame computes the kinetic, potential and mechanical energy of a context.

For that purposes, I have create a DataEngine. This DataEngine has no inputs and has one output, which consist on a struct that contains the energy values for each timestep. The Update method is the following:

    sofa::core::ExecParams params;
    sofa::simulation::common::MechanicalOperations mop(&params, this->getContext());

    SReal kinetic, potential;
    mop.computeEnergy(kinetic, potential);

    Energy *energy = m_energy.beginEdit();
    energy->potentialEnergy.push_back(potential);
    energy->kineticEnergy.push_back(kinetic);
    energy->mechanicalEnergy.push_back(potential + kinetic);
    energy->time.push_back(this->getContext()->getTime());
    m_energy.endEdit();

    setDirtyValue();
    setDirtyOutputs();

The problem with this is that, as I don’t have input Datas, the Update method is not being called unless I open the DataViewer, so I missing a lot of time steps.

I know I could set the positions of a MechanicalObject as an input data, but this is unconvenient as I would like this component to look the energy of a context that may have more than one MechanicalObject.

How could I create a DataEngine component that performs an Update every time step?

Thanks!