There is a TopoDS_Shape and a TopoDS_Edge, how can I get their insect point?
How can I perform a norm project on a given shape with a TopoDS_Vertex?
i'm not sure if there are some possibilities to do this operations on the topo level.... but when you change to geoms there are lot more possibilities. when your edge is only a straight line the fastest method for an intersection would be IntCurvesFace_ShapeIntersector. Otherwise you should look for GeomAPI_IntCS. Or you check your intersection with an extrema function. when they intersect your extrema is a minimum and the distance is 0. check therfor trhe extrema package in Toolkit TKGeomBase .
for projection check GeomAPI_ProjectPointOnSurf()
Thanks for your kindly help! I have solved this problem by extrema method！ Thanks again！