-V     Display the program version and exit.

-v     Make the program produce verbose output.

-t     The  colour  which  is  used  for  transparent  output. Valid range is 0 to 255(default) or 'x' to
       disable.

-l     The number of levels into which the colour-space is divided. Valid range  is  1(default)  to  256.
       Note  that  as of version 1.0 not all output generators obey this parameter or may use a different
       finish type to that specified if the parameter is not 1.

-w     The output target width (x dimension). The source PNG width is used by default.

-h     The output target height (y dimension). Note most outputs will simply ignore  this  parameter  and
       retain the original image aspect ratio based on the width parameter.

-d     The output target depth (z dimension) The number of levels specified is used as the default.

-o     Specifies the output type

       pgm     Output  a  PGM  format  bitmap.  This  can  be  used  to verify the level and quantisation
               parameters are set correctly.
       rscad   Output a scad format file for use with OpenSCAD.  This file will be comprised of  a  union
               of cubes. The finish cannot be controlled (it is raw blocks) and the resulting scad object
               may be very complex.
       scad    Output a scad format file for use with OpenSCAD.  This file will be comprised of a  single
               polyhedron  mesh.   For  larger  images this polygon will be exceptionally complex and may
               contain many thousands of triangles.
       stl     Output a binary stereolithography format  file.   These  files  are  comprised  of  simple
               triangles,  the output can be directly used by several 3D printing systems.  The generated
               meshes are a convex manifold but are not simplified.
       astl    Same as the stl entry but generates a textural file instead of binary.

-f     Specifies the finish out the output 3D mesh the default is cube which keeps all  the  cube  faces.
       The  smooth option uses a marching square algotithm to gives sloped edges and reduces jaggies. The
       rect finish is for the rscad output type only. The  surface  type  generates  a  simple  heightmap
       surface.

-O     Specify the mesh optimisation level of 0, 1(the default) or 2.

       0   No  mesh  optimisation  will be performed. This will be fast to execute but the resulting mesh
           will be exceptionally complex and will  almost  certainly  require  additional  processing  in
           another tool such as meshlab.
       1   Mesh simplification using edge removal algorithm will be performed. This process is relatively
           fast and the result maintains the exact blocky geometry from the generation process. Typically
           this produces reasonable results for non complex extrusions.
       2   Mesh  simplification using quadratic surface removal. This has not yet been implemented! Use a
           tool such as meshlab if you require this type of simplification.

-b     The  bloom  filter  complexity  which  controls  the  size   of   the   filter   and   number   of
       iterations(functions)  used  by  vertex indexing as part of the mesh simplification process. Valid
       range is 0 to 16 with a default of 2. Most users will never need to alter this  parameter.  It  is
       useful only if they are experiencing a high filter miss rate on exceptionally large meshes with 10
       million facets or more).

-m     The filename to save the mesh optimisation debug output to. This is a generated  html  file  which
       graphically  shows  each  stage  of  the  mesh  simplification.  This is useful only for debugging
       purposes and for images above a few hundred  facets  the  output  can  run  to  many  hundreds  of
       megabytes.