Basic options:
&HPPProcessOptions

   hpp_spherical_boundary=F ! Set to T if a spherical hard wall container is used.
   hpp_density=-1 ! Initial density (-1 to not change the density from what it actually is)
   scale_packing=F ! Automatically scale particle sizes to eliminate overlap
   contact_cutoff=0.0 ! Maximal cutoff for neighbouring particles (used for the NNLs as well)

   ! Rendering:
   render_packing=T ! Render using OpenGL
   plot_packing=F ! Make a EPS plot (in 2D) or a VRML scene (in 3D)? The needed VRML files are in the subdirectory VRML
   plot_type="EPS" ! "EPS" or "TIFF"

   ! Correlations:
   compute_g2=F ! Compute pair correlation function? (see namelist HPPDistributionParameters below)
   compute_OPs=T ! Compute some order parameters?
   
   ! Counting neighbours based on proximity:
   count_contacts=F ! Count the number of contacts with gaps in the range 
                    ! 10^Z_gap_range[1]*contact_cutoff to 10^Z_gap_range[2]*contact_cutoff and report to file?
   Z_gap_range=-10 0 ! See above line

   ! Structure factor computation:
   fourier_analyze=F ! Compute S(k) (using FFT)?
   grid_size=50 ! Total grid size to use in FFT
   window_size=10 ! The portion of the grid to output to VTK (visualization) file
   centroids_only=T ! Leave this alone
   normalize_structure_factor=T ! Obvious meaning...

   ! Contact or Voronoi networks: See also namelist HPPNNLParameters below
   ! Further controls are provided below
   ptp_use_nnl=F, ! Compute near-neighbour-lists (NNLs) based on proximity or Voronoi analysis
   read_contacts=F, ! Read the NNLs from a file (file format explained elsewhere)
   read_forces=F, ! Read in contact forces together with the NNLs (force chains can be rendered!)?
   hpp_io_nni_numbering=F, ! Maintain the numbering of contacts (leave as F)
   ! Backbone extraction:
   write_backbone=F, ! If T then the NNLs will be written to a file but only non-rattlers will be included
   Z_cutoff=1, ! Only particles with more contacts than this are counted as non-rattlers
   ! Voronoi tesselations (monodisperse and periodic BCs only for now!)
   voronoi_tessellatation=F ! Delaunay neighbours are included in the NNLs as neighbours  
      ! Note that this automatically writes them to a file
   delanay_cutoff=2 ! Cutoff distance for possible neighbours (must be less than half the box size)
   n_max_delanay_neighbours=64 ! Keep this large
   
/

&HPPNNLParameters
   max_neighbours_="50 50", ! Max neighbours in the NNLs for all particle species
/

For pair correlation functions g2(x=r/D):
&HPPDistributionParameters
   hpp_g2_options%hpp_g2_nonoverlapping=T ! Are the particles non-overlapping (start at r=D) or not (start at r=0)?
   hpp_g2_options%hpp_g2_logarithmic=F ! Use a logarithmic or normal scale for x?
   hpp_g2_options%hpp_g2_n_r_bins=1000 ! Total number of dx bins
   hpp_g2_options%hpp_g2_cutoff=3.0 ! Maximum distance x_max to bin to
   hpp_g2_options%hpp_g2_dmu=0.1 ! For logarithmic scales, this determines the minimal distance x_min
/

Execution options:
&ExecutionHandlerOptions

   log_type="FO" ! Leave alone
   monitor_log_type="FO" ! Leave alone
   log_execution="M" ! "N" for normal, "M" for monitoring (more output), "E" for little to no output to screen
   terminate_execution="E" ! Leave alone
   
   execution_options%execution_random_seed=0 ! If zero than clock will be used to seed the random number generator
   execution_options%register_execution=F ! Leave alone
      
/

OpenGL general rendering options (I do not document most of them)
&OpenGLOptions
   glw_options%glw_name="" ! Name of OpenGL window
   glw_options%glw_filename="" ! The filenames used for image snapshots (blank for default)
   glw_options%glw_file_type="TIFF" ! "EPS" for eps (large files), or "TIFF" (better)
   glw_options%glw_width=600 ! Window width
   glw_options%glw_height=600 ! Window height
   glw_options%glw_offscreen=F ! If T then only images are saved without outputing to screen
   ! If you want to tune the look:
   !glw_options%glw_lookat=0 0 0,
   !glw_options%glw_lookfrom=0 0 5,
   glut_default_menu=T,
   glut_mouse_sensitivity=1, 
   gl_clear_color=0 0 0 1,
   gl_diffuse_color=1 1 1 1,
   gl_ambient_color=0 0 0 1, 
   gl_specular_color=1 1 1 1
/

OpenGL packing-specific rendering options:
&HPPRenderingOptions
   hpr_line_width=2,
   hpr_transparency=0.0,
   hpr_virtual_transparency=0.5,
   hpr_brightness=0.9,
   hpr_specularity=0.0,
   hpr_shininess=0.0,
   hpr_emissivity=0.0,
   hpr_options%hpr_ball_resolution=25,
   hpr_options%hpr_cylinder_resolution=3,
   hpr_options%hpr_render_particles=T,
   hpr_options%hpr_render_boundary=T,
   hpr_options%hpr_render_virtual=F,
   hpr_options%hpr_display_invisible=T,
   hpr_options%hpr_render_contacts=T,
   hpr_options%hpr_render_neighbourhoods=F,
   ! If you don't like the colors
   hpr_options%hpr_particle_colors=1 1 0 1    1 0 1 1,
   hpr_options%hpr_virtual_colors=1 0 0 0.5    0 1 0 0.5,
   hpr_options%hpr_misc_colors=1 1 1 0.5    1 1 1 0.5,
/

! EOF