gluBeginSurface

GLUBEGINSURFACE(3G)					  GLUBEGINSURFACE(3G)



NAME
       gluBeginSurface, gluEndSurface - delimit a NURBS surface definition


C SPECIFICATION
       void gluBeginSurface( GLUnurbs* nurb )

       void gluEndSurface( GLUnurbs* nurb )


PARAMETERS
       nurb  Specifies the NURBS object (created with gluNewNurbsRenderer).

DESCRIPTION
       Use  gluBeginSurface  to mark the beginning of a NURBS surface defini-
       tion. After  calling  gluBeginSurface,  make  one  or  more  calls  to
       gluNurbsSurface	to define the attributes of the surface.  Exactly one
       of these	 calls	to  gluNurbsSurface  must  have	 a  surface  type  of
       GL_MAP2_VERTEX_3	 or  GL_MAP2_VERTEX_4.	 To mark the end of the NURBS
       surface definition, call gluEndSurface.

       Trimming	 of  NURBS   surfaces	is   supported	 with	gluBeginTrim,
       gluPwlCurve,  gluNurbsCurve, and gluEndTrim. See the gluBeginTrim ref-
       erence page for details.

       GL evaluators are used to render the NURBS surface as a set  of	poly-
       gons.	Evaluator   state   is	 preserved   during   rendering	 with
       glPushAttrib(GL_EVAL_BIT) and  glPopAttrib().   See  the	 glPushAttrib
       reference page for details on exactly what state these calls preserve.

EXAMPLE
       The following commands render a textured NURBS surface  with  normals;
       the  texture  coordinates and normals are also described as NURBS sur-
       faces:

       gluBeginSurface(nobj);
	  gluNurbsSurface(nobj, ..., GL_MAP2_TEXTURE_COORD_2);
	  gluNurbsSurface(nobj, ..., GL_MAP2_NORMAL);
	  gluNurbsSurface(nobj, ..., GL_MAP2_VERTEX_4); gluEndSurface(nobj);


SEE ALSO
       gluBeginCurve(3G),     gluBeginTrim(3G),	     gluNewNurbsRenderer(3G),
       gluNurbsCurve(3G), gluNurbsSurface(3G), gluPwlCurve(3G)






							  GLUBEGINSURFACE(3G)