gluNurbsSurface - define the shape of a NURBS surface
void gluNurbsSurface( GLUnurbs* nurb,
GLenum type )
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 paramet-
ric u direction in control.
tStride Specifies the offset (in single-precision floating-point values) between successive control points in the parametric v direc-
tion in control.
control Specifies an array containing control points for the NURBS surface. The offsets between successive control points in the para-
metric 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
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 defi-
nition, 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