A List of Responders
Virtual Manufacturing Background Project
kellihmt@daisymae.crd.ge.com Margaret Kelliher, KW-C218C General Electric PO Box 8 Schenectady NY 12301
The Computer Graphics and Systems Program at General Electrics Corporate R&D
center is currently working in several of the areas you cite as relevant to
Virtual Manufacturing, particularly visualization, environment construction,
modeling, and simulation. We also have an interest in legacy data.
VISUALIZATION and REPRESENTATION:
We have invented many important visualization algorithms, models and
representations including:
- marching and dividing cubes, which create 3D surfaces,
- decimation, a data reduction algorithm to reduce the number of polygon
primitives needed to represent a surface, and
- swept surfaces, in which motion is represented in a static model.
ENVIRONMENT CONSTRUCTION:
We have developed LYMB, an award-winning software development system which
enables rapid construction of new environments using such techniques as rapid
prototyping, graphical user interfaces, 3D computer graphics, advanced
visualization techniques, and distributed processing. It uses an object-
oriented, interpreted software approach and executes on a wide variety of UNIX
workstations. It also provides access to a wide variety of CAD and 3D data
formats. We are currently undertaking an effort to redeploy the system on a PC
platform.
SIMULATION:
We have used LYMB to develop Product Vision, an environment which constructs
digital mockups of large precision machines from CAD models, providing fly-
through capabilities as well as automatic and semi-automatic path generation for
assembly and disassembly planning, and generation of swept surfaces called path
envelopes. These path envelopes are persistent representations of the paths
which are then added back into the CAD systems, providing guidance to designers
about required access spaces.
MODELING TECHNOLOGIES:
We have a program underway to construct a system for capturing as-built dimen-
sions for large precision machines. In order to repair and upgrade this type of
equipment, it is necessary to capture the parts' actual dimensions quickly and
accurately with a minimum of down-time. These dimensions are used to make models
for the manufacture of replacement parts. The measurements are currently taken
and assimilated by hand into paper drawings. We seek to automate parts of this
process and replace paper drawings with electronic models.
INTEGRATION OF LEGACY DATA:
As part of everything we do, we encounter data translation issues. In answer to
this need, we have compiled a library of translation capabilities which are
available to every LYMB application. This is a living library which continues to
grow as we encounter new data sources. We are investigating the issue of legacy
data as a research area of its own, as opposed to an incidental side issue,
researching the possibility of automatic detection of formats and auto-selection
of appropriate translation techniques.
REFERENCES:
WJ Schroeder, WE Lorensen, S Linthicum, "Implicit Modeling of Swept Surfaces
and Volumes", _Proceedings_of_Visualization_'94_, pp 40-45.
WJ Schroeder, JA Zarge, WE Lorensen, "Decimation of Triangle Meshes",
_Computer_Graphics_, Vol. 26 #2, pp 65-70, July 1992.
"1992 Computerworld Object Application Awards", _Computerworld_
WE Lorensen and HE Cline, "Marching Cubes: A High Resolution 3D Surface
Construction Algorithm", _Computer_Graphics_, Vol. 21 #3, pp 163-169, July 1987.
ON-LINE DOCUMENTATION:
http://www.ge.com/crd/img_and_vis_lab.html
A List of Responders
Virtual Manufacturing Background Project
Virtual Manufacturing Home Page