normal(3g) — 4D1 2.0



     normal(3g)                                             normal(3g)



     NAME

          normal - updates the current normal vector


     SPECIFICATION

          C         normal(narray)

                    Coord narray[];



          FORTRAN

                    subroutine normal(narray)

                    real narray(3)


     DESCRIPTION

          normal sets the current normal vector. The x, y, and z world

          coordinates stored in narray are transformed into eye

          coordinates using the inverse transpose of the current

          viewing matrix.  The transformed normal is then available

          for use by the current lighting model.  Normal vectors are
                                              2    2    2
          assumed to be of unit length, thus x  + y  + z  should equal

          1.0.


     SEE ALSO

          lmdef, lmbind


          Programming Guide, Section 14.4


     NOTE

          This routine is available in immediate mode and can be

          called within graphic objects.



























     Page 1                                          (printed 8/20/87)
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