bool write_off(const Surface_mesh& mesh, const std::string& filename)
{
FILE* out = fopen(filename.c_str(), "w");
if (!out)
return false;
// header
fprintf(out, "OFF\n%d %d 0\n", mesh.n_vertices(), mesh.n_faces());
// vertices
Surface_mesh::Vertex_property<Surface_mesh::Point> points = mesh.get_vertex_property<Point>("v:point");
for (Surface_mesh::Vertex_iterator vit=mesh.vertices_begin(); vit!=mesh.vertices_end(); ++vit)
{
const Point& p = points[vit];
fprintf(out, "%.10f %.10f %.10f\n", p[0], p[1], p[2]);
}
// faces
for (Surface_mesh::Face_iterator fit=mesh.faces_begin(); fit!=mesh.faces_end(); ++fit)
{
int nV = mesh.valence(fit);
fprintf(out, "%d", nV);
Surface_mesh::Vertex_around_face_circulator fvit=mesh.vertices(fit), fvend=fvit;
do
{
fprintf(out, " %d", ((Surface_mesh::Vertex)fvit).idx());
}
while (++fvit != fvend);
fprintf(out, "\n");
}
fclose(out);
return true;
}
bool write_obj(const Surface_mesh& mesh, const std::string& filename)
{
FILE* out = fopen(filename.c_str(), "w");
if (!out)
return false;
// comment
fprintf(out, "# OBJ export from Surface_mesh\n");
//vertices
Surface_mesh::Vertex_property<Point> points = mesh.get_vertex_property<Point>("v:point");
for (Surface_mesh::Vertex_iterator vit=mesh.vertices_begin(); vit!=mesh.vertices_end(); ++vit)
{
const Point& p = points[*vit];
fprintf(out, "v %.10f %.10f %.10f\n", p[0], p[1], p[2]);
}
//normals
Surface_mesh::Vertex_property<Point> normals = mesh.get_vertex_property<Point>("v:normal");
for (Surface_mesh::Vertex_iterator vit=mesh.vertices_begin(); vit!=mesh.vertices_end(); ++vit)
{
const Point& p = normals[*vit];
fprintf(out, "vn %.10f %.10f %.10f\n", p[0], p[1], p[2]);
}
//optionally texture coordinates
// do we have them?
std::vector<std::string> h_props= mesh.halfedge_properties();
bool with_tex_coord = false;
std::vector<std::string>::iterator h_prop_end = h_props.end();
std::vector<std::string>::iterator h_prop_start= h_props.begin();
while(h_prop_start!=h_prop_end)
{
if(0==(*h_prop_start).compare("h:texcoord"))
{
with_tex_coord=true;
}
++h_prop_start;
}
//if so then add
if(with_tex_coord)
{
Surface_mesh::Halfedge_property<Texture_coordinate> tex_coord = mesh.get_halfedge_property<Texture_coordinate>("h:texcoord");
for (Surface_mesh::Halfedge_iterator hit=mesh.halfedges_begin(); hit!=mesh.halfedges_end(); ++hit)
{
const Texture_coordinate& pt = tex_coord[*hit];
fprintf(out, "vt %.10f %.10f %.10f\n", pt[0], pt[1], pt[2]);
}
}
//faces
for (Surface_mesh::Face_iterator fit=mesh.faces_begin(); fit!=mesh.faces_end(); ++fit)
{
fprintf(out, "f");
Surface_mesh::Vertex_around_face_circulator fvit=mesh.vertices(*fit), fvend=fvit;
Surface_mesh::Halfedge_around_face_circulator fhit=mesh.halfedges(*fit);
do
{
if(with_tex_coord)
{
// write vertex index, tex_coord index and normal index
fprintf(out, " %d/%d/%d", (*fvit).idx()+1, (*fhit).idx()+1, (*fvit).idx()+1);
++fhit;
}
else
{
// write vertex index and normal index
fprintf(out, " %d//%d", (*fvit).idx()+1, (*fvit).idx()+1);
}
}
while (++fvit != fvend);
fprintf(out, "\n");
}
fclose(out);
return true;
}
