gluPerspective(3G)	       OpenGL Reference		    gluPerspective(3G)



NAME
     gluPerspective - set up a perspective projection matrix


C SPECIFICATION
     void gluPerspective( GLdouble fovy,
			  GLdouble aspect,
			  GLdouble zNear,
			  GLdouble zFar	)


PARAMETERS
     fovy    Specifies the field of view angle,	in degrees, in the y
	     direction.

     aspect  Specifies the aspect ratio	that determines	the field of view in
	     the x direction.  The aspect ratio	is the ratio of	x (width) to y
	     (height).

     zNear   Specifies the distance from the viewer to the near	clipping plane
	     (always positive).

     zFar    Specifies the distance from the viewer to the far clipping	plane
	     (always positive).


DESCRIPTION
     gluPerspective specifies a	viewing	frustum	into the world coordinate
     system.  In general, the aspect ratio in gluPerspective should match the
     aspect ratio of the associated viewport.  For example, aspect=2.0 means
     the viewer's angle	of view	is twice as wide in x as it is in y. If	the
     viewport is twice as wide as it is	tall, it displays the image without
     distortion.

     The matrix	generated by gluPerspective is multipled by the	current
     matrix, just as if	glMultMatrix were called with the generated matrix.
     To	load the perspective matrix onto the current matrix stack instead,
     precede the call to gluPerspective	with a call to glLoadIdentity.


SEE ALSO
     glFrustum,	glLoadIdentity,	glMultMatrix, gluOrtho2D













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