CGAL Remesh , output result has randomness #8719
Description
I am using this function from CGAL to remesh. The preview result looks the same. However, when I tag the face indices on them I can tell the faces are in different orders. And the coordinates of the vertices have very minor differences.
The inputs are the same.
Could anyone tell me if there is anything wrong with my code or if there is a way to get a fixed result?
Thank you very much!
void CGAL_Remesh(double* vert_xyz_array, size_t vert_count, double criteria_a, double criteria_b, int iteration_number, double*& newVertices, int*& vCount, int*& newFaces, int*& fCount)
{ CDT cdt; // insert Vertex_handle
vector<Vertex_handle> cdt_Vh_Boundary;
for (int i = 0; i < vert_count; ++i)
{
Vertex_handle vh = cdt.insert(Point(vert_xyz_array[3 * i + 0], vert_xyz_array[3 * i + 1]));
cdt_Vh_Boundary.push_back(vh);
}
// insert Constrain
for (int i = 0; i < cdt_Vh_Boundary.size() - 1; ++i)
{
cdt.insert_constraint(cdt_Vh_Boundary[i], cdt_Vh_Boundary[i + 1]);
}
cdt.insert_constraint(cdt_Vh_Boundary[cdt_Vh_Boundary.size() - 1], cdt_Vh_Boundary[0]);
// refine and optimize mesh
Mesher mesher(cdt);
mesher.set_criteria(Criteria(criteria_a, criteria_b));
mesher.refine_mesh();
CGAL::lloyd_optimize_mesh_2(cdt, CGAL::parameters::max_iteration_number = iteration_number);
// make index pair
vector<CDT::Vertex_handle> visitedVertices; // collect visited vertices
map<CDT::Vertex_handle, int> indexList; // create a map to note the index
int i = 0;
for (CDT::Vertex_iterator v_it = cdt.vertices_begin(); v_it != cdt.vertices_end(); ++v_it)
{
CDT::Vertex_handle vh = v_it->handle();
indexList[vh] = i;
visitedVertices.push_back(vh);
i++;
}
// Convert data into double array
int vNum = cdt.number_of_vertices();
newVertices = new double[vNum * 3];
i = 0;
for (CDT::Vertex_iterator vi = cdt.vertices_begin(); vi != cdt.vertices_end(); ++vi)
{
newVertices[i] = vi->point()[0];
i += 1;
newVertices[i] = vi->point()[1];
i += 1;
newVertices[i] = 0;
i += 1;
}
int vertexCount = vNum;
vCount = &vertexCount;
int num_face_in_domain = 0;
for (CDT::Face_iterator f_it = cdt.faces_begin(); f_it != cdt.faces_end(); ++f_it)
{
CDT::Face_handle face = f_it;
if (face->is_in_domain())
{
num_face_in_domain++;
}
}
newFaces = new int[num_face_in_domain * 3];
i = 0;
for (CDT::Face_iterator f_it = cdt.faces_begin(); f_it != cdt.faces_end(); ++f_it)
{
CDT::Face_handle face = f_it;
if (face->is_in_domain())
{
newFaces[i] = int(indexList.find(face->vertex(0)->handle())->second);
i += 1;
newFaces[i] = int(indexList.find(face->vertex(1)->handle())->second);
i += 1;
newFaces[i] = int(indexList.find(face->vertex(2)->handle())->second);
i += 1;
}
}
int faceCount = num_face_in_domain;
fCount = &faceCount;
}