ajb@miles.WPI.EDU (Arthur J. Butler) (05/10/91)
here is a summary of the responses i got from my post a few weeks ago
regarding solid modelers and file formats. below is a sorted list of
the info i received. sorry for the delay, but our newsfeed was down.
thanks to all that sent info. if you have anything to add to this,
please let me know.
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Solid modelers, listed alphabetically by name.
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ACIS: Spatial Technology. This is a solid modeling kernel, that is
a set of C functions calls or Library. It was designed to be at the
heart of a CAD system or to be used by other computer programs. See
also Parasolid. Parasolid is more mature, especially in giving you
more functions, including graphics support, ACIS is newer and uses
some new algorithms. Spatial technologies has been donating their
system to lots of Universities whereas McD has not. Acis is soon to
be at the heart of several commercial system (AutoCAD, VersaCAD (I
Think), Schlumberger, and even some of the Big CAD names). An
automatic mesh generation systems has been built using Parasolid by
the folks at PDA (Patran) Engineering.
Alpha_1: University of Utah. Alpha_1 is an excellent NURBS based
solid modeling system develop over the last decade by the University
of Utah. It is the most complete piece of University software I have
ever seen. It comes with two large well written manuals (users &
system), it is very modular, written in C++ and using a client server
approach. Best of all to Universities and the Government it cost
about $ 800. They even include a module for automeshing. Contact
mcminn@cs.utah.edu.
AutoCAD: AutoDesk. AutoCAD with Advanced Modeling Extensions is a
full featured solid modeler (CSG). $4000. It is available for the
SparcStation and will ship an OpenLook driver for free within 45 days.
It has an API that lets you access the solids information.
BRL-CAD: The BRL-CAD Package includes a powerful solid modeling
capability and a network-distributed image-processing capability. This
software is now running at over 400 sites. It has been distributed to
42 academic institutions in twenty states and four countries. 75
different businesses have requested and received the software
including 23 Fortune 500 companies. 16 government organizations
representing all three services, NSA, NASA, NBS and the Veterans
Administration are running the code. Three of the four national
laboratories have copies of the BRL CAD package.
BRL-CAD started in 1979 as a task to provide an interactive graphics
editor for the BRL vehicle-description data base. Today the package
totals more than 150,00 lines of "C" source code. It runs under UNIX
and is supported over more than a dozen product lines from Sun
Workstations to the Cray 2. The package includes:
A Solid geometric editor
The Ray tracing library
Two Lighting models
Many image-handling, data-comparison, and other supporting utilities
In terms of geometrical representation of data, BRL-CAD supports:
The original Constructive Solid Geometry (CSG) BRL database.
Extensions to include solids made from collections of
Uniform B-Spline Surfaces as well as
Non-Uniform Rational B-Spline [NURB] Surfaces.
A faceted data representation.
It supports association of material (and other attribute properties)
with geometry which is critical to subsequent applications codes. It
supports a set of extensible interfaces by means of which geometry
(and attribute data) are passed to applications.
Applications linked to BRL-CAD:
o Weights and Moments-of-Inertia
o Optical Image Generation (including specular/diffuse reflection,
refraction, and multiple light sources, animation, interference)
o Bistatic laser analysis
o A number of Synthetic Aperture Radar Codes (including codes due to ERIM)
o Acoustic model predictions
o High-Energy Laser Damage
o High-Power Microwave Damage
o An array of V/L Codes
o Neutron Transport Code
o Link to PATRAN [TM] and hence to ADINA, EPIC-2, NASTRAN, etc.
for structural/stress analysis
o X-Ray calculation
For more details about what geometric models are useful for, see M.
Muuss, ``Understanding the Preparation and Analysis of Solid Models'',
in ``Techniques for Computer Graphics'', ed: Rogers & Earnshaw,
Springer Verlag, 1987.
To obtain a copy of the BRL CAD Package distribution, you must send
enough magnetic tape for 20 Mbytes of data. Standard nine-track
half-inch magtape is the strongly preferred format, and can be written
at either 1600 or 6250 bpi, in TAR format with 10k byte records. For
sites with no half-inch tape drives, Silicon Graphics and SUN tape
cartridges can also be accommodated. With your tape, you must also
enclose a letter indicating
(a) who you are,
(b) what the BRL CAD package is to be used for,
(c) the equipment and operating system(s) you plan on using,
(d) that you agree to the conditions listed below.
This software is an unpublished work that is not generally available
to the public, except through the terms of this limited distribution.
The United States Department of the Army grants a royalty-free,
nonexclusive, nontransferable license and right to use, free of
charge, with the following terms and conditions:
1. The BRL CAD package source files will not be disclosed to third
parties. BRL needs to know who has what, and what it is being used for.
2. BRL will be credited should the software be used in a product or written
about in any publication. BRL will be referenced as the original
source in any advertisements.
3. The software is provided "as is", without warranty by BRL. In no
event shall BRL be liable for any loss or for any indirect, special,
punitive, exemplary, incidental, or consequential damages arising from
use, possession, or performance of the software.
4. When bugs or problems are found, you will make a reasonable effort
to report them to BRL.
5. Before using the software at additional sites, or for permission
to use this work as part of a commercial package, you agree to first
obtain authorization from BRL.
6. You will own full rights to any databases or images you create
with this package.
All requests should be sent to:
Keith Applin
Ballistic Research Lab
APG, MD 21005-5066
I-DEAS: SDRC. It is a commercially available solid modeler
that runs on Sun Sparcs (as well as several other platforms!)
You could contact someone at (513) 576-2400 for product information or
write
SDRC
2000 Eastman Dr.
Milford, OH 45150
Movie-byu: The movie byu program from bringhham young univ. has a
program called UTILITY which allows for solid model generation using
spheres, hexahedrons, and other geometric primitives. Its a great FEM
pre- and post processor, with many functions for displaying complex
figures and scalar and vector functions superposed over the figure.
Its all in fortran (they give you the source code), and has X drivers
as well as several others.
NOODLES: CMU. Noodles is a solid modeler based on Non Manifold
Topology. It has been developed by Fritz Prinz and Levent Gursoz
(elg@styx.edrc.cmu.edu) I do not know how much they are giving it out.
It has no graphics (that they distribute) but for your application it
has lots of potential)
Parasolid: McDonnell Douglas: This is a solid modeling kernel, that is
a set of C functions calls or Library. It was designed to be at the
heart of a CAD system or to be used by other computer programs. See
also ACIS. Parasolid is more mature, especially in giving you
more functions, including graphics support, ACIS is newer and uses
some new algorithms. Spatial technologies has been donating their
system to lots of Universities whereas McD has not. Acis is soon to
be at the heart of several commercial system (AutoCAD, VersaCAD (I
Think), Schlumberger, and even some of the Big CAD names). An
automatic mesh generation systems has been built using Parasolid by
the folks at PDA (Patran) Engineering.
Pro-Engineer: Parametric Technology Corp. (selling well in Europe)
CSG/BRep hybrid. Feature based modeling. Parametric constraint handling.
Has its own documented neutral file format.
Protosolid: Purdue (vanacek@cs.purdue.edu). Protosolid is a planer
faceted based solid, develop to do robust solids operations (never to
fail). George has also incorporated some Non Manifold topology
features into his modeler which is very useful when doing mesh
generation stuff. He has even done some mesh generation himself. I
do not know if he is giving out copies of his code.
Romulus, used to be Evans and Sutherland (now British again?)
BRep. Powerful boolean operations. Has a good procedural interface to its
data structure.
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Standard formats for solids:
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The ESPRIT project 322 CAD*I (CAD Interafces) has developed a neutral file
format for transfer of CAD data (curves, surfaces and solid models) between
CAD systems and from CAD to CAA (computer aided analysis) and CAM (computer
aided manufacture).
IGES (Version 3.0 I think) is defining standards to transfer solid models -
BRep and CSG. [I feel IGES is getting too bulky these days.]
PDES: As far as solid modeling format, one of the tasks of NIST in
working with DARPA is to get the research community to use PDES an
emerging standard for product model information including solids and
finite element analysis. More information is available via
nptserver@cme.nist.gov put send index in the BODY (not subject line)
of the message, there is tons of stuff available.
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arthur (ajb@miles.wpi.edu)jch@Stardent.COM (Jan Hardenbergh) (05/16/91)
[Good Summary of lots of solid modellers deleted] Of course, the really big names are not mentioned, Computervision, Intergraph, CADAM and CATIA. They only account for over half of the CAD market - based on 1989 market share data from Daratech. CAD/CIM Alert did a survey of Solid Modelling based CAD/CAM systems in a Febuary 28, 1989 issue. They covered 18 companies/products, but missed some such as BRL-CAD. > IGES (Version 3.0 I think) is defining standards to transfer solid models - > BRep and CSG. [I feel IGES is getting too bulky these days.] > > > PDES: As far as solid modeling format, one of the tasks of NIST in > working with DARPA is to get the research community to use PDES an > emerging standard for product model information including solids and > finite element analysis. More information is available via > nptserver@cme.nist.gov put send index in the BODY (not subject line) > of the message, there is tons of stuff available. If you think IGES is too bulky, I do not think you are going to like PDES. The IGES spec is somewhere between 2-3 inches. The PDES spec was about 8 inches or more, last I saw it. -- -Jan "YON" Hardenbergh jch@stardent.com (508)-371-9810x261 Stardent Computer, 6 N.E. Tech Center, 521 Virginia Rd,Concord, MA 01742