David Eck
Department of Mathematics and Computer Science
Hobart and William Smith Colleges
Geneva, NY 14456   USA
E-mail:  eck@hws.edu
WWW:     http://hws3.hws.edu:9000/eck/index.html

June 22, 1995


xModels-2D and xModels-3D are geometric modeling programs, designed to
illustrate the basics ideas of geometric transformations, hierarchical
computer graphics modeling, and animation.  Images are described in a
"scene description language", and scene descriptions are saved as
ordinary text file.  These programs display images only as black and
white wireframe models.

Documentation can be found in the folder "Tutorial Examples" in the form
of extensively commented sample files for use with the programs.  To learn
about the program, read these examples in order.   Two other folders
containing examples are also provided.  If you just want to see what an
example file does, double-click to open it with xModels-2D or -3D, 
and choose the "Render" command from the "Control" menu.

The programs were written to be used with my introductory computer
science text book, _The Most Complex Machine: A Survey of Computers
and Computing_ (A K Peters, Inc., Ltd, Wellesley, MA., ISBN number
1-56881-054-7).  Information about this book, as well as additional
programs and labs to be used with the programs, is available on the
World Wide Web at this URL:

               http://math.hws.edu/TMCM.html

Much of this is also available by anonymouns FTP to math.hws.edu
in the directory /pub/TMCM.  I have included an order form for the
book, just in case you are interested.


COPYRIGHT RESTRICTIONS:  The programs xModels-2D and xModels-3D can
be freely distributed for private, non-commercial use.  I
stipulate, however, that they should not be adopted for use in an
introductory computer science course unless the book _The Most
Complex Machine_ is also adopted.  This material can be included on
inexpensive CD-ROM shareware collections.  It can be made available
for downloading from FTP sites and on-line services, provided that
no charge is made beyond such basic charges as connect time and
membership fee.