What is the corresponding .Net API to "Points From Drawing Objects" for Surface?

[soonhui]

Refer to this screenshot:

Is there a corresponding .Net API that allows me to "Add Points from Drawing Objects", especially 3D Faces?

I also want to "Maintain edges from objects" via the API. 

I can't find how this can be done via TINSurface API, any pointers?

If such convenient API is not available, then I can only do things manually, which involves

1. First adding all the points from the 3D Faces
2. Then rebuild the surface to get the generated edges
3. Compare the generated edge list with the 3D faces edge list, delete the one that is not in the 3D faces edge list, and add in the one that is in the 3D faces edge list.
4. Then I rebuild the surface (?? What does a rebuild actually do, anyway?)

But this might not be always working, because the 3D Faces may not be a Delaunay triangulation-- Delaunay triangulation must consist of 3D triangles, whereas 3D faces can consist of quadrilateral or other shapes. So as I delete and add edges, I don't know what could be the final outcome of the Surface.

Is there a better idea?

[Jeff_M · Accepted solution]

Look at the TinSurface.DrawingObjectsDefinition property.

Rebuild recalculates the points defining the surface.