public void computeNormal(Vector3d normal, double minArea) { computeNormal(normal); if (area < minArea) { Console.WriteLine("area=" + area); // 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(); } }