public static void CalculateTargetPositionForPairContraction(ref MeshPairContraction pair, Vector3[] verts, Quadric[] vertQuadrics)
{
Vector3 v0 = verts[pair.v0], v1 = verts[pair.v1];
Quadric Q0 = vertQuadrics[pair.v0], Q1 = vertQuadrics[pair.v1];
Quadric Q = Q0 + Q1;
if (Q.Optimize(ref pair.contractedPosition, 1e-12))
{
pair.error = Q.Evaluate(pair.contractedPosition);
}
else
{
double ei = Q.Evaluate(v0), ej = Q.Evaluate(v1);
if (ei < ej)
{
pair.error = ei;
pair.contractedPosition = v0;
}
else
{
pair.error = ej;
pair.contractedPosition = v1;
}
}
}
//Returns an array of quadrics for evaluating the error of each possible contraction
public static Quadric[] CalculateVertQuadrics(Vector3[] verts, MeshIndexTriangle[] indexTris)
{
Quadric[] vertQuadrics = new Quadric[verts.Length];
for (int i = 0; i < vertQuadrics.Length; i++)
{
vertQuadrics[i] = new Quadric();
}
foreach (MeshIndexTriangle tri in indexTris)
{
Vector3 v0, v1, v2;
v0 = verts[tri.v0];
v1 = verts[tri.v1];
v2 = verts[tri.v2];
double area = PANELFARTriangleUtils.triangle_area(v0, v1, v2);
Vector4 p;
if (area > 0)
{
p = PANELFARTriangleUtils.triangle_plane(v0, v1, v2);
}
else
{
p = PANELFARTriangleUtils.triangle_plane(v2, v1, v0);
area = -area;
}
Quadric Q = new Quadric(p.x, p.y, p.z, p.w, area);
// Area-weight quadric and add it into the three quadrics for the corners
Q *= Q.area;
vertQuadrics[tri.v0] += Q;
vertQuadrics[tri.v1] += Q;
vertQuadrics[tri.v2] += Q;
}
return(vertQuadrics);
}
