One way of modeling in 3ds Max is with NURBS surfaces and curves. NURBS, which stands for Non-Uniform Rational B-Splines, is an industry standard for designing and modeling surfaces. It is particularly suitable for modeling surfaces with complex curves.
The tools for modeling with NURBS do not require an understanding of the mathematics that produces these objects. NURBS is popular because the objects are easy to manipulate interactively, and because the algorithms that create them are both efficient and numerically stable.
Fountain created as a NURBS model
You can also model surfaces using polygonal meshes or patches. Compared to NURBS surfaces, meshes and patches have these shortcomings:
NURBS surfaces, on the other hand, are analytically generated. They are more efficient to calculate, and you can render a NURBS surface that appears to be seamless. (A rendered NURBS surface is actually approximated by polygons, but the NURBS approximation can be very fine grained.)
Like the Shape object, a NURBS model can be an assemblage of multiple NURBS sub-objects. For example, a NURBS object might contain two surfaces that are separate in space. You control NURBS curves and NURBS surfaces with point or control vertex (CV) sub-objects. Points and CVs behave somewhat like the vertices of spline objects, but there are differences.
NURBS surface objects are the basis of NURBS models. The initial surface you create using the Create panel is a planar segment with points or CVs. It is meant simply to be "raw material" for creating a NURBS model. Once you have created the initial surface, you can modify it on the Modify panel by moving CVs or NURBS points, attaching other objects, creating sub-objects, and so on.
NURBS curves are Shape objects, and you can use them as you do splines. You can use the Extrude or Lathe modifiers to generate a 3D surface based on a NURBS curve. You can use NURBS curves as the path or the shape of a loft. (Lofts created using NURBS curves are loft objects, not NURBS objects.)
These topics describe how to create top-level, “starter” NURBS objects.
These topics describe how to create and edit lower-level, sub-object NURBS.
Topics in this section describe how you can control the way 3ds Max generates NURBS curves and surfaces.
