void gluNurbsSurface
|
( |
GLUnurbs* nurb
, GLint sKnotCount
, GLfloat* sKnots
, GLint tKnotCount
, GLfloat* tKnots
, GLint sStride
, GLint tStride
, GLfloat* control
, GLint sOrder
, GLint tOrder
, GLenum type
); |
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) × (tKnotCount - tOrder) control points.
The following commands render a textured NURBS surface with normals; the texture coordinates and normals are also NURBS surfaces: gluBeginSurface(nobj); gluNurbsSurface(nobj, ..., GL_MAP2_TEXTURE_COORD_2); gluNurbsSurface(nobj, ..., GL_MAP2_NORMAL); gluNurbsSurface(nobj, ..., GL_MAP2_VERTEX_4); gluEndSurface(nobj);