public static void GetVertexFromMinkowsky(
SupportTriangle triangle,
VertexProperties[] vertexShape1,
VertexProperties[] vertexShape2,
ref CollisionPointOutput collisionPoint)
{
Vector3d a1 = vertexShape1[triangle.A.a].Vertex;
Vector3d ba1 = vertexShape1[triangle.B.a].Vertex - a1;
Vector3d ca1 = vertexShape1[triangle.C.a].Vertex - a1;
Vector3d a2 = vertexShape2[triangle.A.b].Vertex;
Vector3d ba2 = vertexShape2[triangle.B.b].Vertex - a2;
Vector3d ca2 = vertexShape2[triangle.C.b].Vertex - a2;
collisionPoint.SetA(
new VertexProperties(a1 + (ba1 * triangle.S) + (ca1 * triangle.T),
new int?[] { vertexShape1[triangle.A.a].ID, vertexShape1[triangle.B.a].ID, vertexShape1[triangle.C.a].ID }));
collisionPoint.SetB(
new VertexProperties(a2 + (ba2 * triangle.S) + (ca2 * triangle.T),
new int?[] { vertexShape2[triangle.A.b].ID, vertexShape2[triangle.B.b].ID, vertexShape2[triangle.C.b].ID }));
}
private double ExecuteGJKAlgorithm(
VertexProperties[] vertexShape1,
VertexProperties[] vertexShape2,
ref CollisionPoint cp,
ref List <SupportTriangle> triangles,
ref Vector3d centroid,
ref bool isIntersection)
{
double minDistance = double.MaxValue;
int minTriangleIndex = -1;
var result = new CollisionPointOutput();
var oldDirection = new Vector3d();
var simplex = new Simplex();
//Primo punto del simplex
simplex.Support.Add(GetFarthestPoint(vertexShape1, vertexShape2, vertexShape2.Length / 2));
//Secondo punto del simplex
Vector3d direction = Vector3d.Normalize(simplex.Support[0].s * -1.0);
if (!simplex.AddSupport(Helper.GetMinkowskiFarthestPoint(vertexShape1, vertexShape2, direction)))
{
return(-1.0);
}
//Terzo punto del simplex
direction = Vector3d.Normalize(GetDirectionOnSimplex2(simplex));
if (!simplex.AddSupport(Helper.GetMinkowskiFarthestPoint(vertexShape1, vertexShape2, direction)))
{
return(-1.0);
}
//Quarto punto del simplex
direction = Vector3d.Normalize(GeometryUtils.CalculateTriangleNormal(
simplex.Support[0].s,
simplex.Support[1].s,
simplex.Support[2].s));
if (!simplex.AddSupport(Helper.GetMinkowskiFarthestPoint(vertexShape1, vertexShape2, direction)))
{
simplex.AddSupport(Helper.GetMinkowskiFarthestPoint(vertexShape1, vertexShape2, -1.0 * direction));
}
//Costruisco il poliedro
centroid = Helper.SetStartTriangle(
ref triangles,
simplex.Support.ToArray());
//Verifico che l'origine sia contenuta nel poliedro
if (Helper.IsInConvexPoly(origin, triangles))
{
isIntersection = true;
return(-1.0);
}
Vector3d triangleDistance = GetMinDistance(ref triangles, origin, ref minTriangleIndex);
result.SetDist(triangleDistance);
result.SetNormal(Vector3d.Normalize(triangleDistance));
Helper.GetVertexFromMinkowsky(triangles[minTriangleIndex], vertexShape1, vertexShape2, ref result);
minDistance = triangleDistance.Length();
for (int i = 0; i < MaxIterations; i++)
{
direction = -1.0 * triangleDistance.Normalize();
if (Vector3d.Length(direction) < constTolerance)
{
direction = origin - centroid;
}
if (direction == oldDirection)
{
break;
}
oldDirection = direction;
if (!simplex.AddSupport(Helper.GetMinkowskiFarthestPoint(vertexShape1, vertexShape2, direction)))
{
for (int j = 0; j < triangles.Count; j++)
{
direction = triangles[j].Normal;
if (!simplex.AddSupport(Helper.GetMinkowskiFarthestPoint(vertexShape1, vertexShape2, direction)))
{
if (simplex.AddSupport(Helper.GetMinkowskiFarthestPoint(vertexShape1, vertexShape2, -1.0 * direction)))
{
break;
}
continue;
}
break;
}
}
triangles = Helper.AddPointToConvexPolygon(triangles, simplex.Support[simplex.Support.Count - 1], centroid);
//Verifico che l'origine sia contenuta nel poliedro
if (Helper.IsInConvexPoly(origin, triangles))
{
isIntersection = true;
return(-1.0);
}
triangleDistance = GetMinDistance(ref triangles, origin, ref minTriangleIndex);
double mod = triangleDistance.Length();
if (mod < minDistance)
{
result.SetDist(triangleDistance);
result.SetNormal(triangles[minTriangleIndex].Normal);
Helper.GetVertexFromMinkowsky(triangles[minTriangleIndex], vertexShape1, vertexShape2, ref result);
minDistance = mod;
}
}
cp = new CollisionPoint(result.A, result.B);
return(minDistance);
}
