IGES
Encyclopedia
CAD data exchange
CAD data exchange involves a number of software technologies and methods to translate data from one Computer-aided design system to another CAD file format...
of information among Computer-aided design
Computer-aided design
Computer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...
(CAD) systems.
The official title of IGES is Digital Representation for Communication of Product Definition Data, first published in January, 1980 by the U.S. National Bureau of Standards as NBSIR 80-1978. Many documents (like early versions of the Defense Standard
Defense Standard
A United States defense standard, often called a military standard, "MIL-STD", "MIL-SPEC", or "MilSpecs", is used to help achieve standardization objectives by the U.S...
s MIL-PRF-28000 and MIL-STD-1840) referred to it as ASME
American Society of Mechanical Engineers
The American Society of Mechanical Engineers is a professional body, specifically an engineering society, focused on mechanical engineering....
Y14.26M, the designation of the ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
committee that approved IGES Version 1.0.
Using IGES, a CAD user can exchange product data models in the form of circuit diagram
Circuit diagram
A circuit diagram is a simplified conventional graphical representation of an electrical circuit...
s, wireframe
Wire frame model
A wire frame model is a visual presentation of a three dimensional or physical object used in 3D computer graphics. It is created by specifying each edge of the physical object where two mathematically continuous smooth surfaces meet, or by connecting an object's constituent vertices using straight...
, freeform surface
Freeform surface modelling
Freeform surface modelling is the art of engineering Freeform Surfaces with a CAD or CAID system.The technology has encompassed two main fields...
or solid modeling
Solid modeling
Solid modeling is a consistent set of principles for mathematical and computer modeling of three dimensional solids. Solid modeling is distinguished from related areas of Geometric modeling and Computer graphics by its emphasis on physical fidelity...
representations
Representation (arts)
Representation is the use of signs that stand in for and take the place of something else. It is through representation that people organize the world and reality through the act of naming its elements...
. Applications supported by IGES include traditional engineering drawing
Engineering drawing
An engineering drawing, a type of technical drawing, is used to fully and clearly define requirements for engineered items.Engineering drawing produces engineering drawings . More than just the drawing of pictures, it is also a language—a graphical language that communicates ideas and information...
s, models for analysis, and other manufacturing
Manufacturing
Manufacturing is the use of machines, tools and labor to produce goods for use or sale. The term may refer to a range of human activity, from handicraft to high tech, but is most commonly applied to industrial production, in which raw materials are transformed into finished goods on a large scale...
functions.
History
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
, General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
, Xerox
Xerox
Xerox Corporation is an American multinational document management corporation that produced and sells a range of color and black-and-white printers, multifunction systems, photo copiers, digital production printing presses, and related consulting services and supplies...
, Computervision
Computervision
Computervision, Inc. was an early pioneer in turnkey Computer Aided Design and Manufacturing . Computervision was founded in 1969 by Marty Allen and Philippe Villers, and headquartered in Bedford, Massachusetts, USA. Its early products were built on a Data General Nova platform...
and Applicon
Applicon
Applicon, Incorporated was one of the first vendors of Computer Aided Design and Manufacturing systems. It was founded in 1969 in Bedford, Massachusetts. During the 1970s and early 1980s, the company had its headquarters and R&D facility in Burlington, MA, while their manufacturing facility was in...
, with the support of the National Bureau of Standards (now known as NIST) and the U.S. Department of Defense (DoD). The name was carefully chosen to avoid any suggestion of a database standard that would compete with the proprietary databases then used by the different CAD vendors.
Since 1988, the DoD has required that all digital
Digital
A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...
Product Manufacturing Information
Product Manufacturing Information
Product and manufacturing information, also abbreviated PMI, conveys non-geometric attributes in 3D computer-aided design and Collaborative Product Development systems necessary for manufacturing product components or subsystems. PMI may include geometric dimensions and tolerances, 3D...
(PMI) for weapons systems contracts (the engineering drawings, circuit diagrams, etc.) be delivered in electronic
Computer file
A computer file is a block of arbitrary information, or resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished...
form, specifically in IGES format. As a consequence, any CAx
CAx
Computer-aided technologies is a broad term that means the use of computer technology to aid in the design, analysis, and manufacture of products....
software vendor who wants to market their product to DoD subcontractors and their partners must support the import (reading) and export (writing) of IGES format files.
An ANSI standard since 1980, IGES has generated enough data to fill warehouses full of magnetic tapes and CD-ROMs of digital PMI for the automotive
Automotive industry
The automotive industry designs, develops, manufactures, markets, and sells motor vehicles, and is one of the world's most important economic sectors by revenue....
, aerospace
Aerospace
Aerospace comprises the atmosphere of Earth and surrounding space. Typically the term is used to refer to the industry that researches, designs, manufactures, operates, and maintains vehicles moving through air and space...
, and shipbuilding
Shipbuilding
Shipbuilding is the construction of ships and floating vessels. It normally takes place in a specialized facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to before recorded history.Shipbuilding and ship repairs, both...
industries, as well as for weapons systems from Trident missile guidance system
Guidance system
A guidance system is a device or group of devices used to navigate a ship, aircraft, missile, rocket, satellite, or other craft. Typically, this refers to a system that navigates without direct or continuous human control...
s to entire aircraft carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...
s. These part models may have to be used years after the vendor of the original design system has gone out of business. IGES files provide a way to access this data decades from now. Today, plugin viewers for Web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
s allow IGES files created 20 years ago to be viewed from anywhere in the world.
After the initial release of STEP (ISO 10303)
ISO 10303
ISO 10303 is an ISO standard for the computer-interpretable representation and exchange of product manufacturing information. Its official title is: Automation systems and integration — Product data representation and exchange...
in 1994, interest in further development of IGES declined, and Version 5.3 (1996) was the last published standard. A decade later, STEP has yet to fulfill its promise of replacing IGES, which remains the most widely used standard for CAx
CAx
Computer-aided technologies is a broad term that means the use of computer technology to aid in the design, analysis, and manufacture of products....
and PMI interoperability.
File format
An IGES file is composed of 80-character ASCIIASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
records, a record length derived from the punched card
Punched card
A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...
era. Text strings are represented in "Hollerith
Hollerith constant
Hollerith constants, named in honor of Herman Hollerith, were used in early FORTRAN programs to allow manipulation of character data.Early FORTRAN had no CHARACTER data type, only numeric types. In order to perform character manipulation, characters needed to be placed into numeric variables via...
" format, the number of characters in the string, followed by the letter "H", followed by the text string, e.g., "4HSLOT" (this is the text string format used in early versions of the Fortran
Fortran
Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
language). Early IGES translators had problems with IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
mainframe computer
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
s because the mainframes used EBCDIC
EBCDIC
Extended Binary Coded Decimal Interchange Code is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems....
encoding for text, and some EBCDIC-ASCII translators would either substitute the wrong character, or improperly set the Parity bit
Parity bit
A parity bit is a bit that is added to ensure that the number of bits with the value one in a set of bits is even or odd. Parity bits are used as the simplest form of error detecting code....
, causing a misread.
Here is a very small IGES file from 1987, containing only two POINT (Type 116), two CIRCULAR ARC (Type 100), and two LINE (Type 110) entities. It represents a slot, with the points at the centers of the two half-circles that form the ends of the slot, and the two lines that form the sides.
The file is divided into 5 sections: Start, Global, Directory Entry, Parameter Data, and Terminate indicated by the characters S, G, D, P, or T in column 73. The characteristics and geometric information for an entity is split between two sections; one in a two record, fixed-length format (the Directory Entry, or DE Section), the other in a multiple record, comma delimited format (the Parameter Data, or PD Section), as can be seen in a more human-readable representation of the file.
S 1
1H,,1H;,4HSLOT,37H$1$DUA2:[IGESLIB.BDRAFT.B2I]SLOT.IGS;, G 1
17HBravo3 BravoDRAFT,31HBravo3->IGES V3.002 (02-Oct-87),32,38,6,38,15, G 2
4HSLOT,1.,1,4HINCH,8,0.08,13H871006.192927,1.E-06,6., G 3
31HD. A. Harrod, Tel. 313/995-6333,24HAPPLICON - Ann Arbor, MI,4,0; G 4
116 1 0 1 0 0 0 0 1D 1
116 1 5 1 0 0D 2
116 2 0 1 0 0 0 0 1D 3
116 1 5 1 0 0D 4
100 3 0 1 0 0 0 0 1D 5
100 1 2 1 0 0D 6
100 4 0 1 0 0 0 0 1D 7
100 1 2 1 0 0D 8
110 5 0 1 0 0 0 0 1D 9
110 1 3 1 0 0D 10
110 6 0 1 0 0 0 0 1D 11
110 1 3 1 0 0D 12
116,0.,0.,0.,0,0,0; 1P 1
116,5.,0.,0.,0,0,0; 3P 2
100,0.,0.,0.,0.,1.,0.,-1.,0,0; 5P 3
100,0.,5.,0.,5.,-1.,5.,1.,0,0; 7P 4
110,0.,-1.,0.,5.,-1.,0.,0,0; 9P 5
110,0.,1.,0.,5.,1.,0.,0,0; 11P 6
S 1G 4D 12P 6 T 1
When displayed, the user should see two yellow
Yellow
Yellow is the color evoked by light that stimulates both the L and M cone cells of the retina about equally, with no significant stimulation of the S cone cells. Light with a wavelength of 570–590 nm is yellow, as is light with a suitable mixture of red and green...
points (hard to see on a white
White
White is a color, the perception of which is evoked by light that stimulates all three types of color sensitive cone cells in the human eye in nearly equal amounts and with high brightness compared to the surroundings. A white visual stimulation will be void of hue and grayness.White light can be...
background, but most CAD systems use a black
Black
Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
background), one located at the origin
Origin (mathematics)
In mathematics, the origin of a Euclidean space is a special point, usually denoted by the letter O, used as a fixed point of reference for the geometry of the surrounding space. In a Cartesian coordinate system, the origin is the point where the axes of the system intersect...
of model space [0,0,0], two red
Red
Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...
circular arcs, and two green
Green
Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometres. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered...
lines.
Foreign Language Support
Due to its growing international popularity (several countries, including AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and the U.K., adopted IGES as their own National Standards for PMI interoperability), support was added to the TEXT (Type 212) entity to support the ISO 8859 (Latin-1)
ISO/IEC 8859-1
ISO/IEC 8859-1:1998, Information technology — 8-bit single-byte coded graphic character sets — Part 1: Latin alphabet No. 1, is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1987. It is informally referred to as Latin-1. It is generally...
alphabet for European characters.
In the 1990s, IGES added support for the JIS encoding
JIS encoding
In computing, JIS encoding refers to several Japanese Industrial Standards for encoding the Japanese language. Strictly speaking, the term means either:* A set of standard character sets for Japanese, notably:...
for Kanji
Kanji
Kanji are the adopted logographic Chinese characters hanzi that are used in the modern Japanese writing system along with hiragana , katakana , Indo Arabic numerals, and the occasional use of the Latin alphabet...
(漢字) as double-byte characters (JIS-6226
JIS X 0208
JIS X 0208 is a 2-byte character set specified as a Japanese Industrial Standard, containing 6879 graphic characters suitable for writing text, place names, personal names, and so forth in the Japanese language. The official title of the current standard is...
), allowing members of the Japan Automobile Manufacturers Association
Japan Automobile Manufacturers Association
Japan Automobile Manufacturers Association, or JAMA, is a trade association with its headquarters in Tokyo, Japan. It was founded in April 1967 and serves as a platform for the automakers of Japan to share technological developments and management practices. There are currently 14 member...
(JAMA) to exchange part models with their American and European partners without loss of the Kanji text.
The current version of IGES does not support Unicode
Unicode
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...
16 or 32 bit character encoding, so Arabic and other scripts (like Thai) cannot be represented.
A Recursive Standard
One of the unique features of the IGES standard is that it was the first ANSIAnsi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
Standard to be documented using itself. Since Version 4.0, all of the technical illustrations for the printed version of the standard have been generated from IGES files. The electronic publishing
Electronic publishing
Electronic publishing or ePublishing includes the digital publication of e-books and electronic articles, and the development of digital libraries and catalogues. Electronic publishing has become common in scientific publishing where it has been argued that peer-reviewed scientific journals are in...
system (LaTeX
LaTeX
LaTeX is a document markup language and document preparation system for the TeX typesetting program. Within the typesetting system, its name is styled as . The term LaTeX refers only to the language in which documents are written, not to the editor used to write those documents. In order to...
) integrates raster images
Raster graphics
In computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
generated from IGES files into the PostScript
PostScript
PostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...
sent to the laser jet computer printer
Computer printer
In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a...
, so text and images are printed on the same page for subsequent use as camera-ready copy for commercial publication. Beginning with IGES Version 5.2, this is how the standard was generated, and Version 5.3 (the most recent ANSI approved version) is available as a PDF document.
Many of the illustrations (all of which conform to the Defense Department's MIL-D-28000 Engineering Drawings Subset of IGES) use the entities that they describe, e.g., the illustration of the LEADER (ARROW) ENTITY (Type 214) can be used as a test case for translator implementers, because it contains all 12 arrow head styles defined by the standard. These WYSIWYG
WYSIWYG
WYSIWYG is an acronym for What You See Is What You Get. The term is used in computing to describe a system in which content displayed onscreen during editing appears in a form closely corresponding to its appearance when printed or displayed as a finished product...
example files can be distinguished by a leading "F" and trailing "X" in the file name (like f214x.igs), and this library is called the IGES X-files by members of the IGES community
Community
The term community has two distinct meanings:*a group of interacting people, possibly living in close proximity, and often refers to a group that shares some common values, and is attributed with social cohesion within a shared geographical location, generally in social units larger than a household...
.
Here is one of the example figures, Figure 2 from Appendix A (fmeparte.igs), that has appeared in every version of IGES since Version 3.0. It uses linear, angular, and ordinate dimension entities, as well as examples of both circular and conic arcs
Conic section
In mathematics, a conic section is a curve obtained by intersecting a cone with a plane. In analytic geometry, a conic may be defined as a plane algebraic curve of degree 2...
. It is usually the first part used when testing an IGES translator, because the standard has a picture of what it should look like.
