private bool DoDeepContact(out ContactData contact)
{
#region Informed search
if (previousState == CollisionState.Separated) //If it was shallow before, then its closest points will be used to find the normal.
{
//It's overlapping! Find the relative velocity at the point relative to the two objects. The point is still in local space!
//Vector3 velocityA;
//Vector3.Cross(ref contact.Position, ref collidableA.entity.angularVelocity, out velocityA);
//Vector3.Add(ref velocityA, ref collidableA.entity.linearVelocity, out velocityA);
//Vector3 velocityB;
//Vector3.Subtract(ref contact.Position, ref localTransformB.Position, out velocityB);
//Vector3.Cross(ref velocityB, ref collidableB.entity.angularVelocity, out velocityB);
//Vector3.Add(ref velocityB, ref collidableB.entity.linearVelocity, out velocityB);
////The velocity is negated because the direction so point backwards along the velocity.
//Vector3.Subtract(ref velocityA, ref velocityB, out localDirection);
//The above takes into account angular velocity, but linear velocity alone is a lot more stable and does the job just fine.
if (collidableA.entity != null && collidableB.entity != null)
Vector3.Subtract(ref collidableA.entity.linearVelocity, ref collidableB.entity.linearVelocity, out localDirection);
else
localDirection = localSeparatingAxis;
if (localDirection.LengthSquared() < Toolbox.Epsilon)
{
localDirection = Vector3.Up;
}
}
if (MPRToolbox.GetContact(collidableA.Shape, collidableB.Shape, ref collidableA.worldTransform, ref collidableB.worldTransform, ref localDirection, out contact))
{
if (contact.PenetrationDepth < collidableA.Shape.collisionMargin + collidableB.Shape.collisionMargin)
state = CollisionState.ShallowContact;
return true;
}
//This is rare, but could happen.
state = CollisionState.Separated;
return false;
//if (MPRTesting.GetLocalOverlapPosition(collidableA.Shape, collidableB.Shape, ref localTransformB, out contact.Position))
//{
// //First, try to use the heuristically found direction. This comes from either the GJK shallow contact separating axis or from the relative velocity.
// Vector3 rayCastDirection;
// float lengthSquared = localDirection.LengthSquared();
// if (lengthSquared > Toolbox.Epsilon)
// {
// Vector3.Divide(ref localDirection, (float)Math.Sqrt(lengthSquared), out rayCastDirection);// (Vector3.Normalize(localDirection) + Vector3.Normalize(collidableB.worldTransform.Position - collidableA.worldTransform.Position)) / 2;
// MPRTesting.LocalSurfaceCast(collidableA.Shape, collidableB.Shape, ref localTransformB, ref rayCastDirection, out contact.PenetrationDepth, out contact.Normal);
// }
// else
// {
// contact.PenetrationDepth = float.MaxValue;
// contact.Normal = Toolbox.UpVector;
// }
// //Try the offset between the origins as a second option. Sometimes this is a better choice than the relative velocity.
// //TODO: Could use the position-finding MPR iteration to find the A-B direction hit by continuing even after the origin has been found (optimization).
// Vector3 normalCandidate;
// float depthCandidate;
// lengthSquared = localTransformB.Position.LengthSquared();
// if (lengthSquared > Toolbox.Epsilon)
// {
// Vector3.Divide(ref localTransformB.Position, (float)Math.Sqrt(lengthSquared), out rayCastDirection);
// MPRTesting.LocalSurfaceCast(collidableA.Shape, collidableB.Shape, ref localTransformB, ref rayCastDirection, out depthCandidate, out normalCandidate);
// if (depthCandidate < contact.PenetrationDepth)
// {
// contact.Normal = normalCandidate;
// }
// }
// //Correct the penetration depth.
// MPRTesting.LocalSurfaceCast(collidableA.Shape, collidableB.Shape, ref localTransformB, ref contact.Normal, out contact.PenetrationDepth, out rayCastDirection);
// ////The local casting can optionally continue. Eventually, it will converge to the local minimum.
// //while (true)
// //{
// // MPRTesting.LocalSurfaceCast(collidableA.Shape, collidableB.Shape, ref localTransformB, ref contact.Normal, out depthCandidate, out normalCandidate);
// // if (contact.PenetrationDepth - depthCandidate <= Toolbox.BigEpsilon)
// // break;
// // contact.PenetrationDepth = depthCandidate;
// // contact.Normal = normalCandidate;
// //}
// contact.Id = -1;
// //we're still in local space! transform it all back.
// Matrix3X3 orientation;
// Matrix3X3.CreateFromQuaternion(ref collidableA.worldTransform.Orientation, out orientation);
// Matrix3X3.Transform(ref contact.Normal, ref orientation, out contact.Normal);
// //Vector3.Negate(ref contact.Normal, out contact.Normal);
// Matrix3X3.Transform(ref contact.Position, ref orientation, out contact.Position);
// Vector3.Add(ref contact.Position, ref collidableA.worldTransform.Position, out contact.Position);
// if (contact.PenetrationDepth < collidableA.Shape.collisionMargin + collidableB.Shape.collisionMargin)
// state = CollisionState.ShallowContact;
// return true;
//}
////This is rare, but could happen.
//state = CollisionState.Separated;
//contact = new ContactData();
//return false;
#endregion
#region Testing
//RigidTransform localTransformB;
//MinkowskiToolbox.GetLocalTransform(ref collidableA.worldTransform, ref collidableB.worldTransform, out localTransformB);
//contact.Id = -1;
//if (MPRTesting.GetLocalOverlapPosition(collidableA.Shape, collidableB.Shape, ref localTransformB, out contact.Position))
//{
// Vector3 rayCastDirection = localTransformB.Position;
// MPRTesting.LocalSurfaceCast(collidableA.Shape, collidableB.Shape, ref localTransformB, ref rayCastDirection, out contact.PenetrationDepth, out contact.Normal);
// MPRTesting.LocalSurfaceCast(collidableA.Shape, collidableB.Shape, ref localTransformB, ref contact.Normal, out contact.PenetrationDepth, out rayCastDirection);
// RigidTransform.Transform(ref contact.Position, ref collidableA.worldTransform, out contact.Position);
// Vector3.Transform(ref contact.Normal, ref collidableA.worldTransform.Orientation, out contact.Normal);
// return true;
//}
//contact.Normal = new Vector3();
//contact.PenetrationDepth = 0;
//return false;
#endregion
#region v0.15.2 and before
//if (MPRToolbox.AreObjectsColliding(collidableA.Shape, collidableB.Shape, ref collidableA.worldTransform, ref collidableB.worldTransform, out contact))
//{
// if (contact.PenetrationDepth < collidableA.Shape.collisionMargin + collidableB.Shape.collisionMargin)
// state = CollisionState.ShallowContact; //If it's emerged from the deep contact, we can go back to using the preferred GJK method.
// return true;
//}
////This is rare, but could happen.
//state = CollisionState.Separated;
//return false;
#endregion
}
