Convert linear/angular impulse to a rigid body to a force/torque vector. If you want to apply a linear or angular impulse to a rigid body, instead of a force or a torque, then you can use this function to convert the desired impulse into a force/torque vector before calling the dBodyAdd... function. This function is given the desired impulse as (ix,iy,iz) and puts the force vector in force. The current algorithm simply scales the impulse by 1/stepsize, where stepsize is the step size for the next step that will be taken.
This function is given a dWorldID because, in the future, the force computation may depend on integrator parameters that are set as properties of the world.