How to get the normal direction of a Geom_Surface object at a point on it

Hi all,

How to get the normal direction of a Geom_Surface object at a point (gp_Pnt) on it?

When I give a gp_Pnt point on the Geom_Surface surface, how can I get the U parameter and V parameter at that point?

Thanks in advance!!

Sharjith Naramparambath's picture

Just try this--

ModelingAlgorithms -> TKGeomAlgo -> GeomAPI -> GeomAPI_ProjectPointOnSurf

Use the GeomAPI_ProjectPointOnSurf::LowerDistanceParameters to get the parameters at the point that is the nearest projection of the point you give in. If the point you input is already on the surface, the UV calculated will for the same point.

Regards
N. Sharjith

zhangzhigang824's picture

Hi Sharjith,

Thanks for your reply, and the method is just right.

thanks again!