Thu, 06/20/2002 - 15:57
Forums:
Hi,
I have a TopoDS_Edge and could get its underlying Geom2d_Curve. I know, that the Geom2d_Curve is a Geom2d_Line. How can I get the start and end point of this line? In the docu it says, a Geom2d_Line is infinite, but my TopoDS_Edge is not infinite. Is there any way to get my start and end points?
Thanks for any help,
Stefan
Thu, 06/20/2002 - 23:06
Stefan
This may not be the best way to do it but if you know the edge to be a line then use a TopExp_Explorer to explore for TopAbs_VERTEX then get the TopoDS_Vertex for each vertex. You can then get the gp_Pnt and finally the gp_XYZ, sort of like this...
for (ex.Init(E, TopAbs_VERTEX); ex.More(); ex.Next()) {
const TopoDS_Vertex &V = TopoDS::Vertex(ex.Current());
gp_Pnt pnt = BRep_Tool::Pnt(V);
gp_XYZ coord = pnt.Coord();
}
Fri, 06/21/2002 - 16:33
Hi Stefan,
there is a lots of tools to do stuff like you want in the class BRep_Tool. If you have your TopoDS_Edge and the TopoDS_Face or Geom_Surface on which the 2d curve is lying, you could use BRep_Tool::CurveOnSurface, and you will get the start and end parameter and the 2d curve that lie on the surface. BRep_Tool::Range could return you the range only also. Look at the class to see all the possibilities.
Good Luck,
Francois.