       SippShadowMapsCreate size
                 The  argument  size  determines  the size of the
              generated depth maps, they will be  (size  x  size)
              "pixels".  When a rendering is performed after this
              function has been called, the generated depth  maps
              are  used  to  create the shadows in the scene. The
              depth maps are  not  deleted  automatically  after-
              wards.  This  is  very  useful if a static scene is
              rendered  several  times,  perhaps  from  different
              viewpoints,  since  the time to generate depth maps
              is only spent once.

              Another usage is to generate the depth maps  before
              some  of the objects are installed in the scene, if
              it is certain that they will never cast a shadow on
              any other object (a floor being a typical example).
              The depth map generation will the  be  considerably
              faster  since  fewer  objects  need to be rendered.
              When the remaining objects are installed, the  ren-
              dering  can be started and shadows is still cast on
              them but not from them.
