Geodesic Dome Design

DOME

Version 4.60
September 22, 1996


What is DOME?

DOME is a program which calculates the properties of a geodesic dome symmetry triangle. DOME calculates spherical vertex coordinates, symmetry triangle topological abundance, and chord factors. DOME supports class I (alternate) and class II (triacon) breakdowns for Icosahedron, Octahedron and Tetrahedron polyhedron types. DOME also supports "Buckyball" formations as well as elliptical geodesics.

Why DOME?

DOME began as a set of geodesic math test algorithims for use in investigating properties of generalized geodesic structures. This continues to be the main purpose of my development of the DOME code. DOME should serve as a basic tool for those interested in geodesic dome design and modeling. All source code is also included in this package and is freely modifiable under the conditions of the GNU General Public License.

System Requirements

DOME has been complied using Borland C++ 4.52 and should run on any PC class system. Dome frequency is limited by the amount of memory available. Full spheres use more memory so the frequency should be reduced accordingly.

Changes From Previous Release Version 4.2

Usage

DOME is run from the DOS command line. The program will terminate with an error message if there is not enough memory to allocate array space for the coordinate matrix. If this occurs, re-run DOME and request a smaller subdivision frequency. Only even frequencies are allowed when using class II.

Usage: dome [-fnnn] [-cn] [-px] [-s or -sb] [-en] [-v] [-w] [-h] [filename.xxx]
Where: -fnnn is geodesic frequency (default nnn=2) -cn is class type (n=1 or 2; default n=1) -px sets the polyhedron type where x is: i for icosahedron (default) o for octahedron t for tetrahedron -s generate full sphere data (default: symmetry triangle) -sb generate a buckyball. Must use class I with frequency equal to a multiple of three. -en enable elliptical formation (default: n=1 circle) n=elliptical eccentricity (n > 0.0 and n < 2.0) -v verbose data display at run-time -w enable wire-frame VRML or DXF output (default: face data) -h displays a help screen filename.xxx is a standard DOS filename where xxx is: DXF, DAT, WRL, POV or PRN

Examples of Usage


File Formats

DOME currently supports five file formats:

Elliptical Structures

DOME allows the creation of elliptical geodesic structures. The -en switch enables this feature. The "n" parameter is the elliptical eccentricity. This value is simply the ratio of the ellipse major axis to ellipse minor axis. A circle has an eccentricity of 1.0.

Dome allows eccentricity values greater than 0.0 but less than 2.0. An eccentricity less than 1.0 results in an ellipse having a semimajor axis = 1.0 and aligned along the x-axis. Likewise, an eccentricity greater than results in an ellipse having a semiminor axis = 1.0 and major axis aligned along the z-axis.

Other Goodies

See the Applied Synergetics Homepage for image samples and links to other Synergetics Web sites. The latest DOME info can be found here.

DOME is also available via ftp from Kirby Urner's Synergetics on the Web site.

DXFtoPOV is a short utility which converts DXF line entities to POV-ray script. This is useful when using a CAD program to modify a DXF file. The modified DXF file can then be rendered using POV-ray. See the source code for more implementation comments.

Recommended Extras

Visit the following sites for freeware that will come in handy using DOME: Note: I can recommend these programs but I cannot support (with the exception of the Struck Utilities) them or guarantee their availablity.

UNIX Portability

Several defines have now been added to the DOME & DXFtoPOV source code to allow porting to UNIX machines.

A Unix/LINUX makefile developed by Chris Fearnley has now been included to improve g++ compilation.

Source Code Comments

Releases of DOME prior to 4.0 had all the source code in one file. DOME 4.60 has the source code split across several files:

DOME Updates

The next major release of DOME will include: Feel free to contact me at rjbono@hiline.net for suggestions, bug reports or questions.

Copyright Information

DOME 4.60, Copyright (C) 1995, 1996 Richard J. Bono

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

Please direct inquiries, comments and modifications to:
Richard J. Bono
44 Augusta Rd.
Brownsville, TX 78521

email: rjbono@hiline.net

Acknowledgements & References

The main reference used in the creation of this code was: "Geodesic Math & How to Use It" by Hugh Kenner, 1976, University of California Press. ISBN 0-520-02924-0; Library of Congress Catalog Card Number: 74-27292. Many thanks to Hugh for putting this data in an accessible format.

Also, many thanks to:
Contact Rick Bono at: rjbono@hiline.net