Hi Mike, it's not a "rebuild", it's an "insert knot line" for surfaces, which will be activated if you have a single face selected and then use Edit > Add pt.


> With that, since points are allowed to be added or removed from a spline curve, could
> that translate to an established surface?

Yeah that's what it does - adds in more control points to a local area of the surface in either the U or V (or both) directions.



> Isn't that something that would be hard to do for a trimmed surface that is already joined to other surfaces?

It actually works ok on a surface that is already joined to others because knot insertion does not change the shape of the surface, the control polygon gets refined with more points but the surface shape stays the same. But usually you would want to do it on a surface that is not joined to others because you won't really see any effect from doing it until you turn on surface control points.

- Michael