2.4. NURBS Surfaces
Basic introduction to NURBS Surfaces in Rhino
Geometry in Rhino can be clasified in Points, Curves, Surfaces, Solids and Primitives. In this chapter we will focus on surfaces, solids and primitives.
Nurbs Surfaces
NURBS > Non-Uniform Rational Basis Spline
Surfaces are bounded by curves called Edges. Surfaces have an area, their shape can be changed by moving control points, and they can be meshed.
Solids
Solids are closed surfaces or polysurfaces that enclose a volume.
Some of the solid primitives are closed single-surfaces, others are polysurfaces.
Polysurface objects are deformable by using the deformation commands.
You can also extract surfaces and deform the surfaces with control Point Editing.
Surface Control Points
Edit points
You can use Point Editing on Curves, Surfaces and Meshes, but not on polysurfaces or solids.
Rhino internally represent Curves as NURBS.
Three things determine the shape of a NURBS Curve:
- A list of points called Control Points
- The Degree
- A list of numbers called Knots
If you change any of these things, it changes the shape of the curve.
Knots
Part of the information needed to define a NURBS curves is a list of numbers called Knot Vector and the values of the numbers in this list are called Knots.
(More info: http://docs.mcneel.com/)
Mesh Surfaces
Work in progress…