public void computeNormal(vector3d normal, double minArea)
{
computeNormal(normal);
if (area < minArea)
{
// make the normal more robust by removing
// components parallel to the longest edge
HalfEdge hedgeMax = null;
double lenSqrMax = 0;
HalfEdge hedge = he0;
do
{
double lenSqr = hedge.lengthSquared();
if (lenSqr > lenSqrMax)
{
hedgeMax = hedge;
lenSqrMax = lenSqr;
}
hedge = hedge.next;
}while (hedge != he0);
point3d p2 = hedgeMax.head().pnt;
point3d p1 = hedgeMax.tail().pnt;
double lenMax = Math.Sqrt(lenSqrMax);
double ux = (p2.x - p1.x) / lenMax;
double uy = (p2.y - p1.y) / lenMax;
double uz = (p2.z - p1.z) / lenMax;
double dot = normal.x * ux + normal.y * uy + normal.z * uz;
normal.x -= dot * ux;
normal.y -= dot * uy;
normal.z -= dot * uz;
normal.normalize();
}
}
