Solid Modeling Solutions: Difference between revisions

Revision as of 20:21, 10 June 2024

Revision as of 20:52, 10 June 2024

Line 12:

==History==

{{Verification|date=June 2023}}

The development of ''Non-Uniform Rational B-Spline'' (NURBS)originated with seminal work at [[Boeing]] and [[SDRC]] (Structural Dynamics Research Corporation) in the 1980s and '90s, a company that led in mechanical computer-aided engineering in those years.<ref>[http://isicad.net/articles.php?article_num=14940 "NURBS and CAD: 30 Years Together"], Ushakov, Dmitry, isicad, December 30, 2011.</ref> Boeing's involvement in NURBS dates back to 1979, when they began developing their own comprehensive CAD/CAM system, TIGER, to support the diverse needs of their aircraft and aerospace engineering groups. Three basic decisions were critical to establishing an environment conducive to developing NURBS. The first was Boeing's need to develop theirits own in-house geometry capability. Specifically, Boeing had special, rather sophisticated,complex surface geometry needs, especially for wing design, that could not be found in any commercially available [[CAD/CAM]] system. As a result, the TIGER Geometry Development Group was established in 1979, and has beenreceived stronglystrong supportedsupport for many years. The second decision critical to NURBS development was the removal ofremoving the constraint of upward geometrical compatibility with the two systems in useused at Boeing at that time. One of these systems had evolved asdue a result ofto the iterative process inherent to wing design., while Thethe other was best suited for adding to the constraints imposed by manufacturing, such as cylindrical and planar regions. The third crucial decision was simple but crucialessential: and addedadding the '"R'" to '"NURBS'." Circles were to be represented exactly:precisely, with no cubic approximations would be allowed.

By late 1979, there were 5 or 6 well-educated mathematicians (PhD's from Stanford, Harvard, Washington and Minnesota) and some had many years of software experience, but none of them had any industrial, much less CAD, geometry experience. Those were the days of the oversupply of math PhDs. The task was to choose the representations for the 11 required curve forms, which included everything from lines and circles to Bézier and B-spline curves.