From:  Michael Gibson
3139.9 In reply to 3139.8 
Hi Burr,

> I think what he was looking for was that drawing program
> type node where all the "points" are actually "on" the curve,
> and they each have "2 handles" (points) that pull out and
> away from the point to create the curvature.

Yeah that is what is called a "Piecewise Bezier" curve type structure.

It's not very good to use for things involving surfacing though, because that kind of a curve is not very smooth - it's made up of a bunch of little 4-point curves that are touching one another and each of those curve pieces are only tangent (G1) to one another and not curvature continuous to one another.

It tends to be harder to see this lack of smoothness when you are only looking it as a 2D outline. Once they are used as a basis for building a surface where the normals are more apparent through shading or reflections the curvature breaks can become more visible.

The NURBS curve method that MoI uses was basically invented specifically to solve this problem and to get a higher quality and smoother type of curve, where there can be more than just 4 points in a single smooth curve piece.

Personally I think the NURBS method is a lot better for 2D curve drawing as well though, because it behaves in a more predictable and uniform manner, the Bezier drawing method involves a kind of strange "bulge things out while drawing" type method while the NURBS curve drawing method lets you move more kind of forwards point by point as you are drawing.

- Michael