GLdouble eyeY,
                                  GLdouble eyeZ,
                                  GLdouble centerX,
                                  GLdouble centerY,
                                  GLdouble centerZ,
                                  GLdouble upX,
                                  GLdouble upY,
                                  GLdouble upZ )

PARAMETERS
       eyeX, eyeY, eyeZ
                       Specifies the position of the eye point.

       centerX, centerY, centerZ
                       Specifies the position of the reference point.

       upX, upY, upZ   Specifies the direction of the up vector.

DESCRIPTION
       gluLookAt  creates  a viewing matrix derived from an eye point, a refer‐
       ence point indicating the center of the scene, and an UP vector.

       The matrix maps the reference point to the negative z axis and  the  eye
       point to the origin.  When a typical projection matrix is used, the cen‐
       ter of the scene therefore maps to the center of  the  viewport.   Simi‐
       larly, the direction described by the UP vector projected onto the view‐
       ing plane is mapped to the positive y axis so that it points  upward  in
       the  viewport.   The UP vector must not be parallel to the line of sight
       from the eye point to the reference point.

       Let
          centerX − eyeX
       F=⎝centerY − eyeY⎠
          centerZ − eyeZ

       Let UP be the vector (upX,upY,upZ).

       Then normalize as follows: f=_____

       UP′=______

       Finally, let s=f×UP′, and u=s×f.

                                            s[0]  s[1]  s[2]  0
       M is then constructed as follows: M=⎝u[0]  u[1]  u[2]  0⎠
                                            −f[0] −f[1] −f[2] 0
                                              0     0     0   1
       and gluLookAt is equivalent to  glMultMatrixf(M);  glTranslated  (-eyex,
       -eyey, -eyez);

SEE ALSO
       glFrustum, gluPerspective