|nurb||Specifies the NURBS object (created with gluNewNurbsRenderer).|
|sKnotCount||Specifies the number of knots in the parametric u direction.|
|sKnots||Specifies an array of sKnotCount nondecreasing knot values in the parametric u direction.|
|tKnotCount||Specifies the number of knots in the parametric v direction.|
|tKnots||Specifies an array of tKnotCount nondecreasing knot values in the parametric v direction.|
|sStride||Specifies the offset (as a number of single-precision floating point values) between successive control points in the parametric u direction in control.|
|tStride||Specifies the offset (in single-precision floating-point values) between successive control points in the parametric v direction in control.|
|control||Specifies an array containing control points for the NURBS surface. The offsets between successive control points in the parametric u and v directions are given by sStride and tStride.|
|sOrder||Specifies the order of the NURBS surface in the parametric u direction. The order is one more than the degree, hence a surface that is cubic in u has a u order of 4.|
|tOrder||Specifies the order of the NURBS surface in the parametric v direction. The order is one more than the degree, hence a surface that is cubic in v has a v order of 4.|
|type||Specifies type of the surface. type can be any of the valid two-dimensional evaluator types (such as GL_MAP2_VERTEX_3 or GL_MAP2_COLOR_4).|
Use gluNurbsSurface within a NURBS (Non-Uniform Rational B-Spline) surface definition to describe the shape of a NURBS surface (before any trimming). To mark the beginning of a NURBS surface definition, use the gluBeginSurface command. To mark the end of a NURBS surface definition, use the gluEndSurface command. Call gluNurbsSurface within a NURBS surface definition only.
Positional, texture, and color coordinates are associated with a surface by presenting each as a separate gluNurbsSurface between a gluBeginSurface/gluEndSurface pair. No more than one call to gluNurbsSurface for each of color, position, and texture data can be made within a single gluBeginSurface/gluEndSurface pair. Exactly one call must be made to describe the position of the surface (a type of GL_MAP2_VERTEX_3 or GL_MAP2_VERTEX_4).
A NURBS surface can be trimmed by using the commands gluNurbsCurve and gluPwlCurve between calls to gluBeginTrim and gluEndTrim.
Note that a gluNurbsSurface with sKnotCount knots in the u direction and tKnotCount knots in the v direction with orders sOrder and tOrder must have (sKnotCount - sOrder) times (tKnotCount - tOrder) control points.
The following commands render a textured NURBS surface with normals; the texture coordinates and normals are also NURBS surfaces:
gluNurbsSurface(nobj, ..., GL_MAP2_TEXTURE_COORD_2);
gluNurbsSurface(nobj, ..., GL_MAP2_NORMAL);
gluNurbsSurface(nobj, ..., GL_MAP2_VERTEX_4); gluEndSurface(nobj);
gluBeginSurface, gluBeginTrim, gluNewNurbsRenderer, gluNurbsCurve, gluPwlCurve