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Comment by KaiserPro | Hacker News Reader

NURBS!

One of my favorite acronyms: Non-Uniform Rational B-Spline. They were very popular in 3D modeling packages like Lightwave years ago.

Are they still used frequently in 3D modeling?

They are the backbone of Rhino CAD, an excellent 3-D design tool.

>They were very popular in 3D modeling packages like Lightwave years ago.

Actually I can't recall Lightwave ever having NURBS, it was all polygon/subdivision surfaces.

Maya has NURBS, and there is NURBS oriented software like Rhino3d, Blender also has rudimentary NURBS support.

>Are they still used frequently in 3D modeling?

I believe it's still the standard for anything requiring precision: computer aided manufacturing/design (CAM, CAD).

Almost all CAD/CAM these days runs on top of the Parasolid geometry kernel. While Parasolid does have b-spline support, it's mostly truely mathematically modeled geometry that is then converted to a poly mesh for rendering - but internally it's all "full precision". It's actually closer to how something like POV-Ray models, rather than NURBS.

In the Film and Animation Industry they have been completely replaced by Sub-Division surfaces. Which offer more flexibility and are easier to work with.

Maya and other software have become heavily focused on Sub-Division surfaces.

Indeed. The main reason they weren't replaced sooner was because parameterizing subdiv and poly surfaces for texturing was historically a pain in the neck, whereas NURBS was essentially free. New techniques like PTex and better UV mapping tools removed that issue, essentially nulling the inherent advantage of NURBS for use as an asset authoring surface type.

It will be interesting to see going forward what happens in games and real time. If something like Pixar's OpenSubDiv will become the de-facto standard for real time geometry or if there will be another paradigm shift to somthing like OpenGL tessellation or something else. Tessellation does not look like it is gaining much traction atm. But then again neither does OpenSubDiv.

I remember when I jumped into the CGI world, NURBS were the big feature in 3DSMAX 2. And it was a huge pain (I guess non optimal math leads to beefy cpu power otherwise it's useless). One day I discover Maya and I realize NURBS are the main surface kind. Except everything was smooth and fluid... on the same very old very weak GPU-less P2 desktop. it's as if the Alias guys were co-authors of The Nurbs Book. Magic.

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