NAME

       plw3d - Configure the transformations required for projecting a 3D surface on a 2D window

SYNOPSIS

       plw3d(basex, basey, height, xmin, xmax, ymin, ymax, zmin, zmax, alt, az)

DESCRIPTION

       Configure  the  transformations  required  for  projecting  a 3D surface on an existing 2D
       window.  Those transformations (see the PLplot documentation) are done  to  a  rectangular
       cuboid enclosing the 3D surface which has its limits expressed in 3D world coordinates and
       also normalized 3D coordinates (used for interpreting the  altitude  and  azimuth  of  the
       viewing  angle).   The  transformations  consist  of  the  linear  transform from 3D world
       coordinates to normalized 3D coordinates, and the 3D rotation  of  normalized  coordinates
       required  to  align  the  pole  of the new 3D coordinate system with the viewing direction
       specified by altitude and azimuth so that  x  and  y  of  the  surface  elements  in  that
       transformed  coordinate  system  are  the  projection of the 3D surface with given viewing
       direction on the 2D window.

       The enclosing rectangular cuboid for the surface plot is  defined  by  xmin,  xmax,  ymin,
       ymax,  zmin  and  zmax  in  3D  world coordinates.  It is mapped into the same rectangular
       cuboid with normalized 3D coordinate sizes of basex by basey by height so that  xmin  maps
       to  -basex/2, xmax maps to basex/2, ymin maps to -basey/2, ymax maps to basey/2, zmin maps
       to 0 and zmax maps to height.  The resulting rectangular cuboid in normalized  coordinates
       is then viewed by an observer at altitude alt and azimuth az.  This routine must be called
       before plbox3(3plplot) or any  of  the  3D  surface  plotting  routines;  plmesh(3plplot),
       plmeshc(3plplot), plot3d(3plplot), plot3dc(3plplot), plot3dcl(3plplot), plsurf3d(3plplot),
       plsurf3dl(3plplot) or plfill3(3plplot).

       Redacted form: plw3d(basex, basey, height, xmin, xmax, ymin, ymax, zmin, zmax, alt, az)

       This function is examples 8, 11, 18, and 21.

ARGUMENTS

       basex (PLFLT(3plplot), input)
              The normalized x coordinate size of the rectangular cuboid.

       basey (PLFLT(3plplot), input)
              The normalized y coordinate size of the rectangular cuboid.

       height (PLFLT(3plplot), input)
              The normalized z coordinate size of the rectangular cuboid.

       xmin (PLFLT(3plplot), input)
              The minimum x world coordinate of the rectangular cuboid.

       xmax (PLFLT(3plplot), input)
              The maximum x world coordinate of the rectangular cuboid.

       ymin (PLFLT(3plplot), input)
              The minimum y world coordinate of the rectangular cuboid.

       ymax (PLFLT(3plplot), input)
              The maximum y world coordinate of the rectangular cuboid.

       zmin (PLFLT(3plplot), input)
              The minimum z world coordinate of the rectangular cuboid.

       zmax (PLFLT(3plplot), input)
              The maximum z world coordinate of the rectangular cuboid.

       alt (PLFLT(3plplot), input)
              The viewing altitude in degrees above the xy plane of  the  rectangular  cuboid  in
              normalized coordinates.

       az (PLFLT(3plplot), input)
              The viewing azimuth in degrees of the rectangular cuboid in normalized coordinates.
              When az=0, the observer is looking face onto the zx plane of the rectangular cuboid
              in  normalized  coordinates,  and  as az is increased, the observer moves clockwise
              around that cuboid when viewed from above the xy plane.

AUTHORS

       Many developers  (who  are  credited  at  http://plplot.sourceforge.net/credits.php)  have
       contributed to PLplot over its long history.

SEE ALSO

       PLplot documentation at http://plplot.sourceforge.net/documentation.php.

                                          November, 2017                           PLW3D(3plplot)