public ConstraintDemo()
{
CollisionShape shape = new BoxShape(new Vector3(HalfExtents, HalfExtents, HalfExtents));
Matrix trans = Matrix.Identity;
trans.Translation = new Vector3(0, 20, 0);
float mass = 1f;
//Point to Point constraint (ball socket)
{
RigidBody bodyA = CreateRigidBody(mass, trans, shape);
trans.Translation = new Vector3(2 * HalfExtents, 20, 0);
mass = 1f;
RigidBody bodyB = null;
//RigidBody bodyB = CreateRigidBody(mass, trans, shape);
//bodyB.ActivationState = ActivationState.DisableDeactivation;
//bodyB.SetDamping(0.3f, 0.3f);
Vector3 pivotInA = new Vector3(HalfExtents, -HalfExtents, -HalfExtents);
Vector3 axisInA = new Vector3(0, 0, 1);
Vector3 pivotInB = bodyB != null?MathHelper.MatrixToVector(MathHelper.InvertMatrix(bodyB.CenterOfMassTransform), MathHelper.MatrixToVector(bodyA.CenterOfMassTransform, pivotInA)) : pivotInA;
Vector3 axisInB = bodyB != null?
Vector3.TransformNormal(Vector3.TransformNormal(axisInA, bodyB.CenterOfMassTransform), MathHelper.InvertMatrix(bodyB.CenterOfMassTransform)) :
Vector3.TransformNormal(axisInA, bodyA.CenterOfMassTransform);
//TypedConstraint p2p = new Point2PointConstraint(bodyA, bodyB, pivotInA, pivotInB);
//TypedConstraint hinge = new HingeConstraint(bodyA, bodyB, pivotInA, pivotInB, axisInA, axisInB);
HingeConstraint hinge = new HingeConstraint(bodyA, pivotInA, axisInA);
//use zero targetVelocity and a small maxMotorImpulse to simulate joint friction
//float targetVelocity = 0.0f;
//float maxMotorImpulse = 0.01;
float targetVelocity = 1.0f;
float maxMotorImpulse = 1.0f;
hinge.EnableAngularMotor(true, targetVelocity, maxMotorImpulse);
PhysicsWorld.AddConstraint(hinge);
}
// create a slider, using the generic D6 constraint
{
mass = 1f;
Vector3 sliderWorldPos = new Vector3(0, 10, 0);
Vector3 sliderAxis = new Vector3(1, 0, 0);
float angle = 0;
Matrix sliderOrientation = Matrix.CreateFromQuaternion(new Quaternion(sliderAxis, angle));
trans = Matrix.Identity;
trans.Translation = sliderWorldPos;
//trans.setBasis(sliderOrientation);
_sliderTransform = trans;
_d6BodyA = CreateRigidBody(mass, trans, shape);
_d6BodyA.ActivationState = ActivationState.DisableDeactivation;
RigidBody fixedBody1 = CreateRigidBody(0, trans, null);
Matrix frameInA, frameInB;
frameInA = Matrix.Identity;
frameInB = Matrix.Identity;
Generic6DofConstraint slider = new Generic6DofConstraint(_d6BodyA, fixedBody1, frameInA, frameInB);
slider.SetLinearLowerLimit(_lowerSliderLimit);
slider.SetLinearUpperLimit(_hiSliderLimit);
//range should be small, otherwise singularities will 'explode' the constraint
slider.SetAngularLowerLimit(new Vector3(10, 0, 0));
slider.SetAngularUpperLimit(new Vector3(0, 0, 0));
PhysicsWorld.AddConstraint(slider);
}
}
