mcminn@wasatch.utah.edu (Glenn W. McMinn) (06/27/89)
The Alpha_1 Geometric Modeling System is an interactive, 3D,
sculptured surface, solid modeling system that has been developed by
the University of Utah's Alpha_1 research group over the last several
years. It is now available under a special free license to university
and government sites for a nominal distribution and media fee.
MODELING
Non-uniform rational B-spline (NURBS) curves and surfaces of arbitrary
order and size comprise the underlying representation for all geometric
entities. Both a graphical user interface and a command language
interface are offered for flexible interaction. The connections
between objects are maintained by the system so that your models are
automatically updated during the modeling process. The Alpha_1 system
combines sculptured surface modeling with constructive solid geometry
to offer a hybrid approach to modeling.
The features of the modeling system include:
o Engineering geometry: points lines, arcs, circles
o Curve and surface constructors: profile, sweep, extrude
o Shape modification operators: bend, flatten, warp
o Grouping and Instancing
o Boolean operations: union, intersect, difference
o Dimensioning
Volumetric primitives as well as mechanical features such as slots,
holes and patterns are defined as primitive objects in the system.
Other objects can be defined by the user by using the parametric
object facility offered in the command language interface to the
system.
GRAPHICS
A wide variety of visualization programs are provided in the system.
Among the features offered are: ray-tracing, a-buffer and z-buffer
shaded rendering, hidden line removal, anti-aliasing and texture
mapping. Images are produced in the Utah Raster Toolkit run length
encoded (RLE) format. The real time shading features of many hardware
platforms also add to the functionality provided by the Alpha_1 system.
Hardcopy output is provided for PostScript and HP plotters.
SYSTEMS ISSUES
The system is written in both C++ and Lisp and currently runs the
following hardware platforms:
o Silicon Graphics: 2000/3000 series, Personal Iris and 4D series
o Hewlett Packard: 300 series, also support for SRX and SRX Turbo
displays
o Digital Equipment Vax and MicroVax
o Sun/3
DOCUMENTATION
The Alpha_1 system is documented with a substantial user's manual.
The manual contains a spline introduction, tutorial, descriptions of
operations, examples, and many illustrations.
DISTRIBUTION
The Alpha_1 system is a flexible, extensible system that has proven to
have many applications in research and teaching environments. The
system is an actively evolving system with new functionality
constantly being added in the areas of geometric modeling, mechanical
design, user interfaces and graphics. Distributions are prepared
approximately twice a year. Distributions are currently scheduled at
the beginning of the summer and during the fall of this year.
The system is distributed by Engineering Geometry Systems (EGS), a
company associated with the Alpha_1 research group and the University
of Utah. Free university and government licenses are currently
available for the nominal distribution and media fee of $475 (plus
$300 for the lisp unless it is already licensed) through EGS. This
price includes the distribution tapes and user's manual. If you want
additional information on Alpha_1 on licensing arrangements, please reply to
mcminn@cs.utah.edu or write to:
Glenn McMinn
Engineering Geometry Systems
275 E. South Temple #305
Salt Lake City, UT 84111