Hi rodney,

> I was going to suggest in the wishlist WIKI that it would
> be super cool to have falloff influences like Modo uses to make
> changes to a surface, i.e. scale that only influences the bottom
> of an object and gradually falls off towards the top (using
> various falloff curves). But I guess this isn't possible?

Well, it is theoretically possible... But it involves a lot more complex stuff than how it works with polygons.

With polygons, you can deform all the "control points" of the mesh the faces stay connected together.

But with a NURBS solid where pieces have been booleaned, the underlying surface's control points are not necessarily aligned with the trim edges, it's more like the edges live on the surface but they only mark different areas of the surface as being active or inactive (inactive areas are holes), the edges don't actually define the shape of the surface, the surface shape completely comes from the "underlying surface" only.


It is possible to do some deformation with NURBS solids by a more complex mechanism though where surfaces are kind of resampled and reconstructed to have a bunch of control points added to them in the areas where you want them to deform, but that method kind of works better for more of "whole object" deformations like bending the whole object at once and not so much for doing sculpting-like tweaks.

If you want behavior more like you are sculpting points, it's really better to work in a polygon modeler for that kind of thing, they are much more set up with that kind of a workflow.

Most of the time in a NURBS modeler you'll be doing things that I'd describe more like "drawing curves and constructing" rather than "sculpting".


When your object is well defined by a set of 2D profile curves (a lot of mechanical type shapes fit into this category), then that's when the NURBS modeling approach works really well.

- Michael