	Heightfield Conversion Utilities -- alpha test version 8/25/95 jpb

Here are some utilities useful for those working with Heightfields (also
called displacement maps or elevation maps or depth maps), especially those
using the POV-Ray raytracer to render them. I decided to release these
early; hence, they may have bugs. However I have run the code sucessfully
using gcc 2.6.3 on at least five different machines (Sparc, SGI, DEC,
Pentium-DOS and Pentium-Linux).

NOTE: be sure to type "make little" if your machine uses IEEE little-endian
format (eg, Intel-based Linux, DEC Ultrix), and "make big" if you've got
IEEE big-endian format.

The "production" release will have more documentation. This is just a
brief description. Run the program with no arguments for an option list.

hcon --  converts between heightfield formats. NOT a general-purpose
converter, only deals with greyscales.

composit -- combines heightfields with several different arithmatic operations.

double --  doubles x and y dimensions of heightfield, some smoothing

copyx -- adds a copy of input heightfield onto the right-hand side; 2x wider.

orb -- generates triangular-mesh spherical 'heightfield' in .raw or POV .inc 
       format. Note: level 5=190k, 6=780k, 7=3meg, 8=13meg, 9=40meg file  

cyl -- generates triangular-mesh cylindrical 'heightfield' in .raw or .inc
       format. args: inner radius, outer radius, length, num_circ, num_high

Look in the 'examples' directory for some sample .POV scenes and a script
demonstrating some of the utilities.

----- <legal stuff> -----------------

hcon, composit, orb, cyl, double, copyx are Copyright (C) 1995 John P. Beale
<beale@jump.stanford.edu>. Released under the GNU Public License version 2
(GPL). Freely redistributable. No fee is requested. No guarantee is given.

I have used Tom Boutell's gd (gifdraw) library for GIF I/O, which requires 
the following notices. GD is

        Written by Tom Boutell, 5/94.
        Copyright 1994, Cold Spring Harbor Labs.
        Permission granted to use this code in any fashion provided
        that this notice is retained and any alterations are
        labeled as such. It is requested, but not required, that
        you share extensions to this module with us so that we
        can incorporate them into new versions. 

        Tom Boutell, boutell@netcom.com
        http://sunsite.unc.edu/boutell/index.html
        116 14th Ave E Apt 2
        Seattle, WA 98102
-------------

The GIF encoder used in GD contains the following additional notices:

   Code drawn from ppmtogif.c, from the pbmplus package
   Based on GIFENCOD by David Rowley <mgardi@watdscu.waterloo.edu>. A
   Lempel-Zim compression based on "compress".
   Modified by Marcel Wijkstra <wijkstra@fwi.uva.nl>
   
   Copyright (C) 1989 by Jef Poskanzer.
   
   Permission to use, copy, modify, and distribute this software and its
   documentation for any purpose and without fee is hereby granted, provided
   that the above copyright notice appear in all copies and that both that
   copyright notice and this permission notice appear in supporting
   documentation.  This software is provided "as is" without express or
   implied warranty.
   
   The Graphics Interchange Format(c) is the Copyright property of
   CompuServe Incorporated.  GIF(sm) is a Service Mark property of
   CompuServe Incorporated.

/* +-------------------------------------------------------------------+ */
/* | Copyright 1990, 1991, 1993, David Koblas.  (koblas@netcom.com)    | */
/* |   Permission to use, copy, modify, and distribute this software   | */
/* |   and its documentation for any purpose and without fee is hereby | */
/* |   granted, provided that the above copyright notice appear in all | */
/* |   copies and that both that copyright notice and this permission  | */
/* |   notice appear in supporting documentation.  This software is    | */
/* |   provided "as is" without express or implied warranty.           | */
/* +-------------------------------------------------------------------+ */
                                                    
