static uint BoxAndHalfSpace(H1Box InBox, H1Plane InPlane, ref H1CollisionDetectResult OutResult)
{
if (!H1PrimitiveIntersection.Intersect(InBox, InPlane))
{
return(0);
}
foreach (H1Vector3 BoxVertex in BoxVertices)
{
// calculate transformed box vertex
H1Vector3 TransformedBoxVertex = H1Vector3.Transform(BoxVertex * InBox.HalfSize, InBox.Transform);
// calculate the distance from the plane
float VertexDistance = H1Vector3.Dot(TransformedBoxVertex, InPlane.Normal);
// compare this to the plane's distance
if (VertexDistance <= InPlane.Distance)
{
// create the contact data
H1CollisionContact Contact = new H1CollisionContact();
Contact.ContactPoint = InPlane.Normal;
Contact.ContactPoint *= (VertexDistance - InPlane.Distance);
Contact.ContactPoint += TransformedBoxVertex;
Contact.ContactNormal = InPlane.Normal;
Contact.Penetration = InPlane.Distance - VertexDistance;
OutResult.Contacts.Add(Contact);
}
}
return(Convert.ToUInt32(OutResult.Contacts.Count));
}
public static float TransformToAxis(H1Box InBox, H1Vector3 InAxis)
{
// think of quater-box (halfsize) end point projecting to InAxis
// which gives maximum distance(by math.abs) toward axis from box
return(InBox.HalfSize.X * Math.Abs(H1Vector3.Dot(InAxis, InBox.Transform.Axis0))
+ InBox.HalfSize.Y * Math.Abs(H1Vector3.Dot(InAxis, InBox.Transform.Axis1))
+ InBox.HalfSize.Z * Math.Abs(H1Vector3.Dot(InAxis, InBox.Transform.Axis2)));
}
public static bool Intersect(H1Ray InRay, H1Bound InBound, out float OutT0, out float OutT1)
{
float T0 = 0.0f;
float T1 = float.MaxValue;
H1Vector3 RayOrigin = InRay.Origin;
for (Int32 SlabIndex = 0; SlabIndex < InBound.SafeSlabs.Count(); ++SlabIndex)
{
// curr slab
H1Slab Slab = InBound.SafeSlabs[SlabIndex];
// slab normal
H1Vector3 SlabNormal = Slab.Normal;
float NominatorPlane0 = Slab[0].Distance - H1Vector3.Dot(Slab[0].Normal, InRay.Origin);
float NominatorPlane1 = Slab[1].Distance - H1Vector3.Dot(Slab[1].Normal, InRay.Origin);
float Denominator = H1Vector3.Dot(InRay.Direction, SlabNormal);
float CurrT0 = NominatorPlane0 / Denominator;
float CurrT1 = NominatorPlane1 / Denominator;
// check if we need to swap
if (CurrT0 > CurrT1)
{
float Temp = CurrT0;
CurrT0 = CurrT1;
CurrT1 = Temp;
}
// if we need to update T0 or T1, update it
if (T0 < CurrT0)
{
T0 = CurrT0;
}
if (T1 > CurrT1)
{
T1 = CurrT1;
}
if (T0 > T1)
{
OutT0 = float.MaxValue;
OutT1 = float.MinValue;
return(false);
}
}
OutT0 = T0;
OutT1 = T1;
return(true);
}
public static bool Intersect(H1Box InBox, H1Plane InPlane)
{
// work out the projected radius of the box onto the plane direction
float ProjectedRadius = TransformToAxis(InBox, InPlane.Normal);
// work out how far the box is from the origin
H1Vector3 BoxPosition = InBox.Transform.Axis3;
float BoxDistance = H1Vector3.Dot(InPlane.Normal, BoxPosition) - ProjectedRadius;
// check for the intersection
return(BoxDistance <= InPlane.Distance);
}
protected void CreatePlanes(H1Vector3 InNormal, H1Vector3 InPosition, float InExtent)
{
H1Vector3 Origin = new H1Vector3(0, 0, 0);
// generate first plane
H1Vector3 PointOnPlane0 = InPosition + InNormal * InExtent;
// calculate distance from origin
float DistanceOnPlane0 = H1Vector3.Dot(PointOnPlane0 - Origin, InNormal);
Planes[0] = new H1Plane(InNormal, DistanceOnPlane0);
// generate second plane
H1Vector3 PointOnPlane1 = InPosition - InNormal * InExtent;
float DistanceOnPlane1 = H1Vector3.Dot(PointOnPlane1 - Origin, InNormal);
Planes[1] = new H1Plane(InNormal, DistanceOnPlane1);
}
