Origin of Computer Aided Design (Part 2)

Origin of Computer Aided Design (Part 2)

Origin of Computer Aided Design - multi-part review of the history

CAD software started its migration out of research and into commercial use in the 1970s. Just as in the late 1960s most CAD software continued to be developed by internal groups at large automotive and aerospace manufacturers, often working in conjunction with university research groups. Throughout the decade automotive manufacturers such as: Ford (PDGS), General Motors (CADANCE), Mercedes-Benz (SYRCO), Nissan (CAD-I released in 1977) and Toyota (TINCA released in 1973 by Hiromi Araki's team, CADETT in 1979 also by Hiromi Araki) and aerospace manufacturers such as: Lockheed (CADAM), McDonnell-Douglas (CADD) and Northrop (NCAD, which is still in limited use today), all had large internal CAD software development groups working on proprietary programs.

Most CAD software programs were still 2D replacements for drafting, with the main benefits to manufacturers being: i) reduced drawing errors, and, ii) increased reusability of drawings. One of the most famous of those 2D CAD software programs, and one which still exists (in name only) more than 30 years later, was the CADAM (Computer Augmented Drafting and Manufacturing) system originally developed by the Lockheed aircraft company. In 1975 the French aerospace company, Avions Marcel Dassault, purchased a source-code license of CADAM from Lockheed and in 1977 began developing a 3D CAD software program named CATIA (Computer Aided Three Dimensional Interactive Application) which survives to this day as the most commercially successful CAD software program in current use.

The 1970s started with simple 2D CAD software programs such as CADAM but research and commercial interest in 3D CAD software was rapidly gaining momentum and one of the most influential pieces of research of the decade was in complex 3D surface modeling for CAD software. K. Vesprille's (at Syracuse University) 1975 PhD dissertation "Computer-Aided Design Applications of the B-Spline Approximation Form", built on the 1960s research of deCasteljau, Bezier, Coons and Forrest and earlier (1973) work by R.F.Risenfeld (also at Syracuse University) and continues to be one of the foundations of complex 3D curve and surface modeling in 3D CAD software to this day.

The first 3D solid modeling program, SynthaVision from MAGI (Mathematics Application Group, Inc.) was released in 1972, not as CAD software but as a program for performing 3D analysis of nuclear radiation exposure. SynthaVision's 3D models were solid models similar to the CSG (constructive solid geometry) models used by later 3D CAD software. In general though, and despite steadily increasing computer performance, solid modeling was still too compute intensive for most practical applications. Extensive solid modeling research was done by Charles Lang's group (at Cambridge University) and by Herb Voelcker and his team (at the University of Rochester's Production Automation Project) throughout the decade and the approaches taken throughout the 1970s by the two groups were fundamentally different, as were the CAD software products ultimately based on their research.

Herb Voelcker's efforts focused on CSG solid modeling and resulted in the 1978 release of the PADL (Part and Assembly Description Language) solid modeler, which was subsequently used in several commercial 3D solid modeling CAD software programs in the early 1980s. B-rep (boundary representation) data structures had been proposed by B. Baumgart (at Stanford University) in the early 1970s for their advantages in finte-element meshing applications but it was Ian Braid, working in Charles Lang's group at Cambridge University, who released prolific research on the applications of b-rep in solid modeling throughout the mid 1970s to culminate in the 1978 release of the BUILD solid modeler, the first true boundary representation solid modeler implementation. Shortly after that release, Ian Braid moved into Shape Data Ltd. a CAD software consulting company which had been established by Charles Lang, Ian Braid and others in Cambridge in 1974.

The increasing power of computers, and especially the introduction of lower cost minicomputers with optimized Fortran compilers and graphics capable terminals, were beginning to make CAD software more accessible to engineers. The commercial CAD software market was emerging and by the end of the decade was to be very strong and profitable. The increasingly widespread development and use of CAD software was prompting calls for some form of standardization and in late 1979, Boeing, General Electric and the NBS (then the National Bureau of Standards, now NIST, the National Institute of Standards) agreed to commence the first implementation of IGES (Initial Graphic Exchange Standard), which was published the following year. IGES facilitated the transfer of complex 3D curves and surfaces between different 3D CAD software programs and despite other initiatives continues to be the most widely used data-transfer format in CAD software to the present time.

Many CAD software vendors were founded in the 1970s and many new commercially available CAD software programs were released. In 1970 M&S Computing (later to become Intergraph) was established while in the following year Dr. Hanratty founded MCS. In 1972 MCS released the ADAM CAD software which was rapidly licensed as an OEM product by other CAD software companies, including Computervision, Gerber Scientific and United Computing and was used as the core (or kernel) of their commercial CAD software systems.

By the end of the decade, the first wave of true commercial CAD software vendors had formed and many automotive, aerospace and consumer electrical/electronics companies were using some amount of commercially available CAD software in conjunction with their proprietary, internally specified and developed CAD software programs. Commercial CAD software included: Auto-trol's Auto-Draft, Calma, Computervision's CADDS, IBM's CADAM (marketed on behalf of Lockheed), M&S Computing's IGDS (Interactive Graphics Design Software) and McAuto's Unigraphics (the result of McAuto's 1976 acquisition of United Computing) all contending to capture share in the new and dynamic CAD software market. The CAD software and hardware market had grown from under $25M in 1970 to just under $1B in 1979, with investor interest in CAD software vendors mirroring that trend. Not surprisingly, in 1979 Auto-trol became the first CAD software vendor to successfully complete a public offering.

The 1970s then was a decade which saw major advances in CAD software, especially in the fundamental geometric algorithms that CAD software was built on. Equally important, the power of computer hardware was steadily increasing while the new VAX minicomputers launched by DEC, by 1979 second only to IBM in market share, and minicomputers from Data-General, HP and Prime were continuing to reduce computer prices and operating costs and making CAD software accessible to smaller companies. In the late 1970s new high-level programming languages such as C and simpler operating systems such as UNIX were emerging into more wide-scale use and the first generation of graphics capable desktop computers (such as Hewlett-Packard's HP9845 series in 1978) was encouraging engineers to experiment with programming and heralding the dawn of workstation computing.