Hi Brian,

re:
> 1/22/2020, face.dropPoint(pt), yields 2D uv of surface point, closest to input pt.
> So pt just has to be close to surface, or could be a point on an isoline.

The point given to face.dropPoint() can actually be anywhere, it will find the closest point on the surface from the input point.


> I figure that a point (say the center point of a circle), could be acted on by a force, either
> attractive or repulsive, move to pt2, and a new point on surface found, with new circle
> aligned to new surface normal. What is the time overhead?

Well it depends a lot on the complexity of the surface and also the complexity of the trimming boundaries. It does have to do quite a bit of work but you could probably do a few hundred calls.

- Michael