This shape node represents a NURBS surface based on the node's knot vectors and on control points constructed from the current coordinates. The current coordinates are used in row-major order (the V direction corresponds to the rows). The number of coordinates used is determined by the numUControlPoints and numVControlPoints fields. The uKnotVector and vKnotVector fields contain floating point arrays of non-decreasing values.

The order of the surface in the U and V directions is defined as the number of knots minus the number of control points in the particular direction. The largest order allowed for a NURBS surface is 8.

The control points of the NURBS surface are transformed by the current cumulative transformation. The surface is drawn with the current light model and drawing style. The coordinates, normals, and texture coordinates of a surface are generated, so you cannot bind explicit normals or texture coordinates to a NURBS surface. The first material in the state is applied to the entire surface.

The surface is trimmed according to the currently defined profile's curves.

When default texture coordinates are applied to a NURBS surface, the edges of the texture square are stretched to fit the surface. The axes of the texture are called S and T; S is horizontal and T is vertical. The axes of the NURBS surface are called U and V; U is horizontal and V is vertical. You can also define texture coordinates explicitly with the S,T location point, the knot vectors, and the current texture coordinates.

The approximation of the surface by polygons is affected by the current complexity value.