What are T-Splines? Print
"T-Splines are the next thing... They have opened up possibilities to work with surfaces that were simply impossible before." — Eric Allen, Production Manager, DAZ
T-Splines: A new modeling surface for design

T-Splines are a powerful computer-aided design (CAD) surface with special properties, which improves upon traditional CAD technology while retaining compatibility.

T-Splines allows designers to

  • Add detail only where necessary
  • Create non-rectangular topology
  • Easily edit complex freeform models
  • Maintain NURBS compatibility

Since T-Splines is compatible with existing modeling technologies, it integrates easily with most production pipelines.

Add detail only where necessary

T-Splines surfaces can contain areas with differing levels of detail. Control points may be added only where needed. A typical T-Splines surface will have up to 50% fewer control points than the identical equivalent set of NURBS surfaces.

T-Splines are similar to NURBS, with the difference that you can have partial isoparms.

A main difference between T-Splines and NURBS is the existence of T-points. A T-point is a vertex where on one side, there is an isoparm, and on the other side, there isn't. This allows lines of detail to end elegantly. The surface is always smooth (C2) at a T-point. NURBS don't allow T-points.

Partial isoparms and T-points
Create non-rectangular topology

Extrusions, holes, and other unique features are easy to create in a T-Spline surface. This is a second difference between T-Splines and NURBS. NURBS require multiple surfaces, or a polysurface, for such objects. T-Splines can accomodate these features in a single surface, through using a special point called a star point.

T-Splines are like subdivision surfaces in this respect, with the difference that you can insert geometry without changing the surface.

Star points allow a single T-spline surface to be non-rectangular
Easily edit complex freeform models.

Because of T-points and star points, T-Splines surfaces are easy to edit--simply grab a point anywhere on the surface and move it. The surface will stay smooth and gaps will not be introduced.

Maintain NURBS compatibility

If your downstream applications require a different file format, T-Spline models can be exactly converted to NURBS. T-Splines can also be exported as a mesh.

T-Spline car T-Spline car converted to NURBS