function RotationalMotorEquation(bodyA, bodyB, maxForce){
    maxForce = typeof(maxForce)!=='undefined' ? maxForce : 1e6;
    Equation.call(this,bodyA,bodyB,-maxForce,maxForce);

    /**
     * World oriented rotational axis
     * @property {Vec3} axisA
     */
    this.axisA = new Vec3();

    /**
     * World oriented rotational axis
     * @property {Vec3} axisB
     */
    this.axisB = new Vec3(); // World oriented rotational axis

    /**
     * Motor velocity
     * @property {Number} targetVelocity
     */
    this.targetVelocity = 0;
}
Rotational motor constraint. Tries to keep the relative angular velocity of the bodies to a given value.
@class RotationalMotorEquation
@constructor
@author schteppe
@param {Body} bodyA
@param {Body} bodyB
@param {Number} maxForce
@extends Equation