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gluNurbsSurface.3gl
Langue: en
Version: 382996 (fedora - 01/12/10)
Section: 3 (Bibliothèques de fonctions)
NAME
gluNurbsSurface - define the shape of a NURBS surfaceC SPECIFICATION
void gluNurbsSurface( GLUnurbs* nurb,GLint sKnotCount, GLfloat* sKnots, GLint tKnotCount, GLfloat* tKnots, GLint sStride, GLint tStride, GLfloat* control, GLint sOrder, GLint tOrder, GLenum type )
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PARAMETERS
- 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).
DESCRIPTION
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.EXAMPLE
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);
SEE ALSO
gluBeginSurface(3G), gluBeginTrim(3G), gluNewNurbsRenderer(3G), gluNurbsCurve(3G), gluPwlCurve(3G)Contenus ©2006-2024 Benjamin Poulain
Design ©2006-2024 Maxime Vantorre