Understanding NURBS

- NURBS is a type of curve-based modelling that's used very widely in industrial design. So many of the man-made objects that we use in our daily lives, were probably designed using some form of NURBS. And so if you're creating a model in 3ds Max that fits that profile, that's some sort of man-made object, then NURBS may be a good approach for you to take. It could be a good modeling modality for you to explore. In an intro course, we really only have time to scratch the surface of the NURBS toolset, but in this chapter, we'll take a quick look at how you can constuct NURBs objects and edit them, and also set up their tessellation properties so that they will render nice and smoothly.

I've got this modernist end table here, and the base was built using very simple NURBS tools. Let's take a quick look at this so we can learn a little bit about how NURBS work in 3ds Max. I'll select it and go into the Modify panel, and you'll see that there are three Sub-Object Types listed here. Surface, Curve CV or Control Vertex, and Curve. And the object is listen as a NURBS Surface. But sometimes you might actually see a situation in which it says NURBS Curve up here at the top, but actually includes a surface, which is kind of paradoxical.

Basically in 3ds Max, there's only one type of NURBS object. And it may be labeled as a Curve or it may be labeled as a Surface. And it could potentially include a Surface Sub-Object, or a Curve Sub-Object, or both. Currently, we have all of the above here. There's a Surface Sub-Object, and if I select that and then click the object, we'll need to be in wireframe to see it. If I hit F3, you'l see that we get this red outline here. Those are the isol lines of the Surface.

Those are the areas where the Surface has minimal curvature. All right, then we can try another one of these. There's Curve. And these are the actual curves that make up this surface. I'm going to switch back to shaded mode with F3. We can click on those and you can see those individual curves. And if I move those around, I can control the shape, as you can see here. So the surface is dependent upon the curves. I want to do that. The curves themselves are made up of control vertices, just like Bézier spline is.

We go to Curve CV. Then we can select individual points on those curves, and again, edit them to change the shape of the object. I want to do that. That's a basic introduction to how NURBS work in 3ds Max. Next, we'll look at building up a surface from a series of surves.