Hi All I am having problem with the add_edge function. I have a graph that has more than 3 million edges from a triangulation. When I try to fill the graph with these edges the program terminates. I have filled the graph with approximately 1 500 000 successfully but it will not take in more. Sample code is below //Code typedef adjacency_list < listS, vecS, undirectedS, VertexProperty, EdgeProperty > sGraph m_graph; m_graph = sGraph(m_scan.size()); // scan size is 2 500 000 pair e; typedef graph_traits < sGraph >::vertex_descriptor Vertex u, v; //Filling the graph FORALLfacets { if(!facet->upperdelaunay) { qh_makeridges(facet); FOREACHridge_(facet->ridges) { if(!ridge->seen) { int i = 0; v_id.clear(); FOREACHvertex_(ridge->vertices) { v_id.push_back(qh_pointid (vertex->point)); i++; } //add edges to the graph u = v_id[0]; v = v_id[1]; e = add_edge(u, v , m_graph);//terminates after filling the graph with approximately 2 000 000 edges ridge->seen = 1; float d = m_scan[u].distance3D(m_scan[v]); //put(edge_length_t(), m_graph, e.first, d); } } } } I have recently started using Boost Graph Libraries and would like yo know if I am doing something wrong. Thanks WTM -- -------------------------------------------- Willard Mapurisa, ComputaMaps Private Bag X20, Constantia 7848, South Africa tel: +27.21.700 8140, fax: +27.21.701 9520, cell: +27.79.8045714 e-mail: wmapurisa@computamaps.com Manufacturers of digital maps and imagery http://www.computamaps.com --------------------------------------------