/// <summary>
/// Populates a list with transformed face vertices.
/// </summary>
public static unsafe void ComputeFaceClippingPolygon(ref NativeBuffer <ClipVertex> output, int faceIndex, RigidTransform t, NativeHull hull)
{
Debug.Assert(output.IsCreated);
NativeFace * face = hull.GetFacePtr(faceIndex);
NativePlane plane = hull.GetPlane(faceIndex);
NativeHalfEdge *start = hull.GetEdgePtr(face->Edge);
NativeHalfEdge *current = start;
do
{
NativeHalfEdge *twin = hull.GetEdgePtr(current->Twin);
float3 vertex = hull.GetVertex(current->Origin);
float3 P = math.transform(t, vertex);
ClipVertex clipVertex;
clipVertex.featurePair.InEdge1 = -1;
clipVertex.featurePair.OutEdge1 = -1;
clipVertex.featurePair.InEdge2 = (sbyte)current->Next;
clipVertex.featurePair.OutEdge2 = (sbyte)twin->Twin;
clipVertex.position = P;
clipVertex.hull2local = vertex;
clipVertex.plane = plane;
output.Add(clipVertex);
current = hull.GetEdgePtr(current->Next);
} while (current != start);
}
public static unsafe void QueryEdgeDistance(out EdgeQueryResult result, RigidTransform transform1, NativeHull hull1, RigidTransform transform2, NativeHull hull2)
{
// Perform computations in the local space of the second hull.
RigidTransform transform = math.mul(math.inverse(transform2), transform1);
float3 C1 = transform.pos;
result.Distance = -float.MaxValue;
result.Index1 = -1;
result.Index2 = -1;
for (int i = 0; i < hull1.EdgeCount; i += 2)
{
NativeHalfEdge *edge1 = hull1.GetEdgePtr(i);
NativeHalfEdge *twin1 = hull1.GetEdgePtr(i + 1);
Debug.Assert(edge1->Twin == i + 1 && twin1->Twin == i);
float3 P1 = math.transform(transform, hull1.GetVertex(edge1->Origin));
float3 Q1 = math.transform(transform, hull1.GetVertex(twin1->Origin));
float3 E1 = Q1 - P1;
float3 U1 = math.rotate(transform, hull1.GetPlane(edge1->Face).Normal);
float3 V1 = math.rotate(transform, hull1.GetPlane(twin1->Face).Normal);
for (int j = 0; j < hull2.EdgeCount; j += 2)
{
NativeHalfEdge *edge2 = hull2.GetEdgePtr(j);
NativeHalfEdge *twin2 = hull2.GetEdgePtr(j + 1);
Debug.Assert(edge2->Twin == j + 1 && twin2->Twin == j);
float3 P2 = hull2.GetVertex(edge2->Origin);
float3 Q2 = hull2.GetVertex(twin2->Origin);
float3 E2 = Q2 - P2;
float3 U2 = hull2.GetPlane(edge2->Face).Normal;
float3 V2 = hull2.GetPlane(twin2->Face).Normal;
if (IsMinkowskiFace(U1, V1, -E1, -U2, -V2, -E2))
{
float distance = Project(P1, E1, P2, E2, C1);
if (distance > result.Distance)
{
result.Index1 = i;
result.Index2 = j;
result.Distance = distance;
}
}
}
}
}
public static unsafe void GetFaceSidePlanes(ref NativeBuffer <ClipPlane> output, NativePlane facePlane, int faceIndex, RigidTransform transform, NativeHull hull)
{
NativeHalfEdge *start = hull.GetEdgePtr(hull.GetFacePtr(faceIndex)->Edge);
NativeHalfEdge *current = start;
do
{
NativeHalfEdge *twin = hull.GetEdgePtr(current->Twin);
float3 P = math.transform(transform, hull.GetVertex(current->Origin));
float3 Q = math.transform(transform, hull.GetVertex(twin->Origin));
ClipPlane clipPlane = default;
clipPlane.edgeId = twin->Twin; //edge ID.
clipPlane.plane.Normal = math.normalize(math.cross(Q - P, facePlane.Normal));
clipPlane.plane.Offset = math.dot(clipPlane.plane.Normal, P);
output.Add(clipPlane);
current = hull.GetEdgePtr(current->Next);
}while (current != start);
}
public static unsafe void CreateEdgeContact(ref NativeManifold output, EdgeQueryResult input, RigidTransform transform1, NativeHull hull1, RigidTransform transform2, NativeHull hull2)
{
Debug.Assert(output.IsCreated);
ContactPoint cp = default;
if (input.Index1 < 0 || input.Index2 < 0)
{
return;
}
NativeHalfEdge *edge1 = hull1.GetEdgePtr(input.Index1);
NativeHalfEdge *twin1 = hull1.GetEdgePtr(edge1->Twin);
float3 P1 = math.transform(transform1, hull1.GetVertex(edge1->Origin));
float3 Q1 = math.transform(transform1, hull1.GetVertex(twin1->Origin));
float3 E1 = Q1 - P1;
NativeHalfEdge *edge2 = hull2.GetEdgePtr(input.Index2);
NativeHalfEdge *twin2 = hull2.GetEdgePtr(edge2->Twin);
float3 P2 = math.transform(transform1, hull2.GetVertex(edge2->Origin));
float3 Q2 = math.transform(transform1, hull2.GetVertex(twin2->Origin));
float3 E2 = Q2 - P2;
float3 normal = math.normalize(math.cross(Q1 - P1, Q2 - P2));
float3 C2C1 = transform2.pos - transform1.pos;
if (math.dot(normal, C2C1) < 0)
{
// Flip
output.Normal = -normal;
cp.Id.FeaturePair.InEdge1 = input.Index2;
cp.Id.FeaturePair.OutEdge1 = input.Index2 + 1;
cp.Id.FeaturePair.InEdge2 = input.Index1 + 1;
cp.Id.FeaturePair.OutEdge2 = input.Index1;
}
else
{
output.Normal = normal;
cp.Id.FeaturePair.InEdge1 = input.Index1;
cp.Id.FeaturePair.OutEdge1 = input.Index1 + 1;
cp.Id.FeaturePair.InEdge2 = input.Index2 + 1;
cp.Id.FeaturePair.OutEdge2 = input.Index2;
}
// Compute the closest points between the two edges (center point of penetration)
ClosestPointsSegmentSegment(P1, Q1, P2, Q2, out float3 C1, out float3 C2);
float3 position = 0.5f * (C1 + C2);
//// the closest points on each hull
//cp.positionOnTarget = Math3d.ProjectPointOnLineSegment(P2, Q2, C2);
//cp.positionOnSource = Math3d.ProjectPointOnLineSegment(P1, Q1, C1);
cp.Penetration = C1 - C2;
cp.Position = position;
cp.Distance = input.Distance;
output.Add(cp);
}