Applying external forces on models

[ZSciamma]

Hello,

Firstly, thank you for making this amazing library available! I am currently using it to make a simple physics-based game. Is there a built-in way to control an object in real-time, or apply external forces on an object?

I would like the player to be able to control the main character, which is a simple cube rigid body. I haven't yet figured out the best way to do this. The way I have been doing it is to listen to keyboard input, then effectively apply a force on the cube when the player presses a key. In order to apply forces, for now I've added a line to Simulation/TimeStepController.cpp in the TimeStepController::step() function, as such:

// Simulation/TimeStepController.cpp, line 84
// Existing code
clearAccelerations(model);
SimulationModel::RigidBodyVector &rb = model.getRigidBodies();
ParticleData &pd = model.getParticles();
OrientationData &od = model.getOrientations();

// New line
ForceController::setExternalForceAcceleration(model);

This function, setExternalForceAcceleration(), fetches the player object, gets its acceleration vector, and adds the new force to the acceleration vector using force/mass. The ForceController class monitors keyboard input to keep track of the force to be added to make the cube move. But I suspect that there's some feature in the library that I don't know about.

Is there a built-in way to control objects in real time, or a built-in way to add external forces to an object, and if not, is there a way you would recommend going about it?

Thank you so much in advance!

[janbender]

I think your solution should work. I also would add such forces directly before the PBD solver starts iterating.