//From triangle where each triangle has one vertex to half edge public static List <HalfEdge> TransformFromTriangleToHalfEdge(List <Triangle> triangles) { //Make sure the triangles have the same orientation MeshOperations.OrientTrianglesClockwise(triangles); //First create a list with all possible half-edges List <HalfEdge> halfEdges = new List <HalfEdge>(triangles.Count * 3); for (int i = 0; i < triangles.Count; i++) { Triangle t = triangles[i]; HalfEdge he1 = new HalfEdge(t.v1); HalfEdge he2 = new HalfEdge(t.v2); HalfEdge he3 = new HalfEdge(t.v3); he1.nextEdge = he2; he2.nextEdge = he3; he3.nextEdge = he1; he1.prevEdge = he3; he2.prevEdge = he1; he3.prevEdge = he2; //The vertex needs to know of an edge going from it he1.v.halfEdge = he2; he2.v.halfEdge = he3; he3.v.halfEdge = he1; //The face the half-edge is connected to t.halfEdge = he1; he1.t = t; he2.t = t; he3.t = t; //Add the half-edges to the list halfEdges.Add(he1); halfEdges.Add(he2); halfEdges.Add(he3); } //Find the half-edges going in the opposite direction for (int i = 0; i < halfEdges.Count; i++) { HalfEdge he = halfEdges[i]; Vertex goingToVertex = he.v; Vertex goingFromVertex = he.prevEdge.v; for (int j = 0; j < halfEdges.Count; j++) { //Dont compare with itself if (i == j) { continue; } HalfEdge heOpposite = halfEdges[j]; //Is this edge going between the vertices in the opposite direction if (goingFromVertex.position == heOpposite.v.position && goingToVertex.position == heOpposite.prevEdge.v.position) { he.oppositeEdge = heOpposite; break; } } } return(halfEdges); }
public Triangle(HalfEdge halfEdge) { this.halfEdge = halfEdge; }