How to verify that a point or a set of uv parameters are on the actual surface?

Hi
Please help.
I have imported a STEP with a cylinder. One of the surfaces (actually it is a circle) has ortogonal UV parameters (it is aligned with the x and y axis).
I need to find intersection with a line (curve). I use GeomAPI_IntCS, which works fine until intersection points are outside the circle, but inside the U min,max range and Vmin,max range. The GeomAPI_IntCS finds that these points are on the surface.
How to verify that a point or a set of uv parameters are on the actual surface and not just within the limits of the uv paramenters?

The GeomAPI_ProjectPointOnSurf and Extrema_ExtPS find that the outside circle points are on the surface.
/lars

Neng's picture

Hi Lars,

the points are actually on the surface (bounded by the uv params), just not on the face (your circle, as part of the imported shape). Try BRepClass_FaceClassifier to find out the state (TopAbs_State ON or IN) of a point on a face at given uv params and with a certain tolerance.
Example: http://www.opencascade.org/org/forum/thread_10577/.
Good luck,

Tina