View Full Version : Nurbs

09-17-2004, 12:33 PM
What is the difference between Nurbs and sub-patching and why doesn't Lightwave support Nurbs?

09-17-2004, 04:06 PM
Nurbs stands for Non Uniform Rational B-spline. Metanurbs are calculated differently from nurbs.

Lw doesn't support them basically because of tradition. It's never had them and previous teams never decided they were useful for the cost of putting them in I guess. Maybe the new team will.

You do have access to splnes and can extrude etc these, which you could then metanurb, it's up to you :)

09-21-2004, 02:00 PM
Lightwave's Modeler is fundamentally poly and / or spline based. It also applies what was once called "MetaNurbs" - a nurbs / poly hybrid approach to modelling.

Imo it's a fab truly intuitive system. You can tab between polys and organic subdivisions so you get the best of both worlds. Check out the artwork in the Gallery sections of this site. It's possible to produce anything imaginable in Lightwave.

09-21-2004, 07:38 PM
Nurbs are nice if you have a modeler that will work correctly. The previous modeler I used crashed too much. Anyways, If you used the bezier tool, you kind of get an idea of nurbs. The difference is that bezier tool drops a spline and can not be reactivated on that spline. Nurbs can be activated when ever you click on it for editing. Also a nurbs point can allow more than two vertexes to be attached to it. Usually four vertexes but modelers may differ in the number of vertexes. When you edit a nurb you can move a point in any one of the three axises like you can a spline. However a nurb still retains the control handles similar to bezier handles. Except that a nurbs point has a control handle for each vertex attached to it. So if there are four vertexes attached then there are four control handles. Also you can copy a vertex and drag it along the object. For example if you had a nurbs ball, and it had four vertexes going around the ball and four connecting vertexes holding the round vertexes together. You can select one vertex say the middle round vertex, copy it and move that vertex up or down the ball and the ring would change in diameter to match that of the ball. Once in place you could then move the points or ring to change the shape of the ball.
The biggest problem I had with my old modeler was converting nurbs to polys or polys to nurbs. Sometimes the object did not keep it's shape. I think one reason had to do with nurbs being one side objects like in LW and the polys were double sided. Oh well, we all move on. Perhaps one day NT will add nurbs. But for my money I rather had a rock solid modeler than a flashy modeler that don't deleiver.