       Texture mappings algorithms are supported for primitive
              objects:

              Each object primitive which can be created in  SIPP
              has an argument that describes what kind of texture
              coordinates should be assigned to  the  surface  of
              the object. This parameter can have one of the fol-
              lowing predefined values:

                 o NATURAL - This value tell SIPP to  use  a  two
                 dimensional  mapping which is "natural" for this
                 particular object. It might be one of the  other
                 available  mappings  or  it  might  be something
                 unique for the object.  The description  of  the
                 functions  for  creating  the individual objects
                 specifies how this mapping is done.

                 o CYLINDRICAL - A two dimensional  mapping.  The
                 coordinates  are  assigned as if the object were
                 projected on a cylinder surrounding  the  object
                 and  centered  on the z-axis object. The coordi-
                 nates are mapped so that `x' goes from  0  to  1
                 around  the  base  of  the cylinder and `y' goes
                 from 0 to 1 from bottom to top on it.

                 o SPHERICAL - Same  as  `CYLINDRICAL',  but  the
                 object  are projected on a sphere surrounding it
                 instead.

                 o WORLD - A three dimensional mapping. The  tex-
                 ture  coordinates are the same three dimensional
                 coordinates as  the  world  coordinates  of  the
                 object at creation time.
