The intersection class constructor references surface objects, but the intersection object does not own them. The surface objects are linked to the intersection object. On deletion or modification of one of them, internal intersection results are marked as invalid and to be re-computed. 

Computation of the intersection does not happen on construction or Set(), but on demand from one of the query functions. 

Any output geometry from an intersection object is owned by the caller.

Public Sub New(
    surface2 As Surface, 
    surface1 As Surface
)

public SurfaceSurfaceIntersector(
    Surface surface2, 
    Surface surface1
);