I’ve been meaning to get around to this subject for a long time.

NURBS modeling has traditionally been the feature that separated the upper-tier and lower-tier professional 3D packages. Softimage and Alias (and now Maya) had it, and MAX and Lightwave did not. Bringing NURBS to MAX has been the centerpiece of Kinetix’s effort to position the program in the upper tier, or at least to smear the distinction between the tiers. NURBS arrived in MAX last year in the 2.0 version of the program, but in mine (and, I think, most people’s) view, the tools did not function well enough to be taken seriously. NURBS implementations involve extremely sophisticated programming, and many observers wondered whether one could ever find a place in a $3,000 program.

By MAX Version 2.5, the NURBS implementation began to work well enough to demand attention. I’m currently writing a book on the upcoming 3.0 version of MAX, and have been working with the new release in beta for the past few months. I can comfortably say that in MAX 3, NURBS will have fully arrived. It’s with a view to this evident future that I’d like to spend the next few columns on this subject. MAX 3 has added a number of important features to the existing NURBS implementation, but we can safely ignore these and focus on what’s already in MAX 2.5 (and will work better in MAX 3).

We last looked at NURBS in the context of Softimage, and you may want to take a look at those lessons. NURBS modeling is extremely challenging to learn at anything above the trivial level, and there are a number of reasons for this. First, the entire approach to building geometry out of curves is non-intuitive for most organic modeling purposes. If a sculptor wishes to fashion a human head out of clay, he or she would start with a block and shape it. Push in the orbits of the eyes. Pull out a nose. This is exactly what one does in organic polygonal modeling, and is best exemplified in Lightwave’s MetaNURBS toolset (which are NOT NURBS, but polygonal). It is much harder to visualize the head as a network of curves that can be connected into surfaces. So, whatever the implementation, NURBS modeling is very difficult for fundamental artistic reasons.

Another reason that NURBS is so difficult is that the toolsets are very complex, and necessarily foreign to anyone first approaching them. There is so much to learn before you can do anything at all. There’s no easy way to start. Still another difficulty with NURBS is the extremely complex and subtle mathematical principles on which they are based. You can’t control things that you don’t understand, and you can’t use NURBS effectively without a good grasp of the geometry of curved surfaces. And this just happens be one of the most subtle and forbidding aspects of modern math.

Any sane person would have to ask whether we really need NURBS. Is NURBS modeling really worth the trouble? The jury is out on this one. Polygonal modeling tools just keep getting better. NURBS were the center of MAX’s efforts to beef up its organic modeling tools, but MAX 3 is implementing such greatly improved polygonal modeling tools that many people may never get around to NURBS. My feeling, right now, is that it’s time to get a good handle on NURBS modeling if you’re a MAX user so that you can properly assess the role it may play in your work. And if you’re not a MAX user, you may decide that you want to become one.

So let’s get started.