#
Alpha_1: Advanced Experimental CAD Modeling System

### Goal

Based on project research results, the Alpha_1 system is an advanced
research software base, supporting use and research in geometric
modeling (both ab initio and reverse engineering), high-quality
graphics, curve and surface representations and algorithms,
engineering design, analysis, visualization, process planning, and
computer-integrated manufacturing.

### Approach

Solid models in Alpha_1 are represented by trimmed B-spline (NURBS)
sculptured-surface boundary representations. That is, the surfaces of
a solid are represented explicitly, and linked together by shared
edges. Our NURBS are Non-Uniform knot vector, Rational B-Splines of
arbitrary order with tensor-product surfaces trimmed by NURBS
curves. Alpha_1, implemented in C++, provides both command-language
and graphical, menu-driven interfaces.

An extensive 2D and 3D geometric modeling environment supports
user-oriented operations for building up parts from dimensions,
through basic geometry (points, lines, arcs, circles, etc.) through
curve and surface constructions (profiles, sweeps, extrusions, etc.),
shape operations (bend, twist, warp, etc.), and finally solids and
boolean expressions (union, intersection, and difference) of solids.

Time-varying models support animation, linkage design, simulations, etc.
Volumetric primitives (box, cylinder, sphere, etc.) are represented by
"parametric object types" which generate and cache spline-surfaced solid
representations on demand. Similarly, mechanical design "features" (holes,
pockets, etc.) may be grouped to support automatic CNC machining code
generation within a context of machine setups, fixturing, etc. High-level
parameterized procedural modeling "power-tools" are easily built up to
encapsulate and automate design and manufacturing strategies.

### Technology Transfer

The Alpha_1 software is licensed to our University tech-transfer company,
Engineering Geometry Systems (EGS). The
only software based on Alpha_1 which is publicly available at this time is
the FeatureCam
machining product from EGS.

### Participants

### Publications

### Support

This project is a Utah State Center of Excellence. The group's
research and facilities are sponsored by ARPA, NSF, the NSF STC for
Computer Graphics and Scientific Visualization, and various industrial
sponsors.

gdc-web@cs.utah.edu
*Last update: January 7, 2000*