T-Splines: Breathing New Life into NURBS

By Matthew Sederberg, T-Splines, LLC

I enjoy reading the forums at highend3d and other sites to see what the current buzz is about. I am particularly interested in discussions that debate the relative merits of NURBS and subds. From the standpoint of our company, we hope that these debates will eventually die down because T-Splines will predominate.

T-Splines is breathing new life into NURBS, the decades-old modeling standard in CAD, industrial design, and animation. Using NURBS is viewed as a necessary evil by many of the modelers I have talked with: they need the precision NURBS gives, but dealing with tangencies between patches, seaming, and manipulating is a headache. T-Splines allows modelers to keep all the benefits of NURBS, but not worry about most of these problems. T-Splines allows modelers to create seamless models when they would have used multiple patches in NURBS. This is possible because of our patent-pending T-Junctions, which facilitate incredible amounts of detail in desired areas of the model, while keeping the rest of the model light�every portion of the model only contains the number of control points necessary to maintain the shape in that area. So one way to view T-Splines is that they are the way NURBS ought to be.

However, there is much more to T-Splines than merely a set of nice tools for NURBS modeling�the advantages of T-Splines also extend to subds. Mathematically, T-Splines can do anything that subds can do, because a subd is a special case of a T-Spline just like a NURBS is a special case of a T-Spline. But T-Splines can do important things that subds cannot do, such as adding geometry without changing the surface.

Finally, T-Splines are compatible with both NURBS and subds. The importance of compatibility cannot be over emphasized. Companies and industries that heavily use NURBS or subds have a huge investment in software and models. Economics discourage such companies from adopting new ways of modeling that are incompatible with the prevailing methods.

For those reasons, T-Splines can make a legitimate claim to being the future of 3d modeling. T-Splines incorporates the best of NURBS and subds, and since it�s fully compatible with both, can fit easily into existing pipelines.
The Maya community is the first with access to T-Splines, although T-Splines will soon be available for most major modeling packages (we are currently preparing a release for Rhino).

The T-Splines Maya Plugin Version 1 was designed to accommodate two basic workflows: using T-Splines to create a new model and converting existing models to T-Splines for simplification.


There are a number of ways to take advantage of T-Splines when creating a new model. Since the main advantage of T-Splines is in editing and detail work, many artists create the general shape of their model with polygons, then convert to T-Splines to add detail and make changes. It is also effective to begin modeling directly in T-Spline or NURBS primitives.


As 3d models become more and more realistic, every industry is demanding more high-detailed models. Achieving this level of detail in NURBS or polygons can result in heavy models that are unwieldy to edit and expensive to render. By converting existing NURBS and polygon models to T-Splines, you can subsequently cleanse the model of unneeded data and merge multiple-patch NURBS models into a single surface. This results in a T-Spline model that is easy to manipulate and edit, and accommodates areas of high detail while leaving less detailed areas of the surface uncluttered with control points.

You can download the free learning edition of the T-Splines Maya Plugin and try T-Splines today. Leverage our online tutorials, movies, and downloadable documentation to get up to speed quickly.


.