Index for Section 3

Alphabetical listing for G

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gluNurbsSurface()
NAME
  gluNurbsSurface - define the shape of a NURBS surface

SYNOPSIS
  void gluNurbsSurface(
	  GLUnurbs* nurb,
	  GLint sKnotCount,
	  GLfloat* sKnots,
	  GLint tKnotCount,
	  GLfloat* tKnots,
	  GLint sStride,
	  GLint tStride,
	  GLfloat* control,
	  GLint sOrder,
	  GLint tOrder,
	  GLenum type );

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(3), gluBeginTrim(3), gluNewNurbsRenderer(3),
  gluNurbsCurve(3), gluPwlCurve(3)

Index for Section 3

Alphabetical listing for G

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