public override void ProcessCollision(CollisionObject bodyA, CollisionObject bodyB, DispatcherInfo dispatchInfo, ManifoldResult resultOut)
{
CollisionObject convexBody = _isSwapped ? bodyB : bodyA;
CollisionObject triBody = _isSwapped ? bodyA : bodyB;
if (triBody.CollisionShape.IsConcave)
{
CollisionObject triOb = triBody;
ConcaveShape concaveShape = triOb.CollisionShape as ConcaveShape;
if (convexBody.CollisionShape.IsConvex)
{
float collisionMarginTriangle = concaveShape.Margin;
resultOut.SetPersistentManifold(_convexTriangleCallback.Manifold);
_convexTriangleCallback.SetTimeStepAndCounters(collisionMarginTriangle, dispatchInfo, resultOut);
//Disable persistency. previously, some older algorithm calculated all contacts in one go, so you can clear it here.
//m_dispatcher->clearManifold(m_btConvexTriangleCallback.m_manifoldPtr);
_convexTriangleCallback.Manifold.SetBodies(convexBody, triBody);
concaveShape.ProcessAllTriangles(_convexTriangleCallback, _convexTriangleCallback.AabbMin, _convexTriangleCallback.AabbMax);
}
}
}
public override float CalculateTimeOfImpact(CollisionObject bodyA, CollisionObject bodyB, DispatcherInfo dispatchInfo, ManifoldResult resultOut)
{
CollisionObject convexbody = _isSwapped ? bodyB : bodyA;
CollisionObject triBody = _isSwapped ? bodyA : bodyB;
//quick approximation using raycast, todo: hook up to the continuous collision detection (one of the btConvexCast)
//only perform CCD above a certain threshold, this prevents blocking on the long run
//because object in a blocked ccd state (hitfraction<1) get their linear velocity halved each frame...
float squareMot0 = (convexbody.InterpolationWorldTransform.Translation - convexbody.WorldTransform.Translation).LengthSquared();
if (squareMot0 < convexbody.CcdSquareMotionThreshold)
{
return(1);
}
Matrix triInv = MathHelper.InvertMatrix(triBody.WorldTransform);
Matrix convexFromLocal = triInv * convexbody.WorldTransform;
Matrix convexToLocal = triInv * convexbody.InterpolationWorldTransform;
if (triBody.CollisionShape.IsConcave)
{
Vector3 rayAabbMin = convexFromLocal.Translation;
MathHelper.SetMin(ref rayAabbMin, convexToLocal.Translation);
Vector3 rayAabbMax = convexFromLocal.Translation;
MathHelper.SetMax(ref rayAabbMax, convexToLocal.Translation);
float ccdRadius0 = convexbody.CcdSweptSphereRadius;
rayAabbMin -= new Vector3(ccdRadius0, ccdRadius0, ccdRadius0);
rayAabbMax += new Vector3(ccdRadius0, ccdRadius0, ccdRadius0);
float curHitFraction = 1f; //is this available?
LocalTriangleSphereCastCallback raycastCallback = new LocalTriangleSphereCastCallback(convexFromLocal, convexToLocal,
convexbody.CcdSweptSphereRadius, curHitFraction);
raycastCallback.HitFraction = convexbody.HitFraction;
CollisionObject concavebody = triBody;
ConcaveShape triangleMesh = concavebody.CollisionShape as ConcaveShape;
if (triangleMesh != null)
{
triangleMesh.ProcessAllTriangles(raycastCallback, rayAabbMin, rayAabbMax);
}
if (raycastCallback.HitFraction < convexbody.HitFraction)
{
convexbody.HitFraction = raycastCallback.HitFraction;
return(raycastCallback.HitFraction);
}
}
return(1);
}
