gluUnProject

GLUUNPROJECT(3G)					     GLUUNPROJECT(3G)



NAME
       gluUnProject - map window coordinates to object coordinates


C SPECIFICATION
       GLint gluUnProject( GLdouble winX,
			   GLdouble winY,
			   GLdouble winZ,
			   const GLdouble *model,
			   const GLdouble *proj,
			   const GLint *view,
			   GLdouble* objX,
			   GLdouble* objY,
			   GLdouble* objZ )


PARAMETERS
       winX, winY, winZ
		       Specify the window coordinates to be mapped.

       model	       Specifies the modelview matrix (as from a glGetDoublev
		       call).

       proj	       Specifies the projection matrix (as from	 a  glGetDou-
		       blev call).

       view	       Specifies the viewport (as from a glGetIntegerv call).

       objX, objY, objZ
		       Returns the computed object coordinates.

DESCRIPTION
       gluUnProject maps the specified window coordinates into object coordi-
       nates  using  model,  proj,  and	 view.	The result is stored in objX,
       objY, and objZ. A return value of GL_TRUE indicates success; a  return
       value of GL_FALSE indicates failure.

       To compute the coordinates (objX, objY, and objZ), gluUnProject multi-
       plies the normalized device coordinates by the inverse  of  model*proj
       as follows:


			  objX
					_______________−1


















			  objY
					_______________−1








			 (    )=INV(PM)(		 )









			  objZ
					    2(winZ)−1


















			   W
						1












































































































       INV() denotes matrix inversion.	W is an unused variable, included for
       consistent matrix notation.

SEE ALSO
       glGet(3G), gluProject(3G)



							     GLUUNPROJECT(3G)