Solid Modeling Solutions: Difference between revisions

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NURBS ([[non-uniform rational B-spline]]), 3D geometry, and [[solid modeling]] technology emerged in the 1980s and 1990s into a commercial implementation known as SMLib (for solid modeling library). This article will provide the background and history of this implementation into a commercial product line from [http://www.smlib.com Solid Modeling Solutions]™ (SMS). SMS is an independent supplier of source code for a suite of NURBS-based geometry libraries, SMLib™SMLib, TSNLib™TSNLib, GSNLib™GSNLib, NLib™NLib, SDLib™SDLib, VSLib™VSLib, and PolyMLib™PolyMLib, that encompass definition and manipulation of NURBS curves and surfaces with the latest fully functional non-manifold topology.

VSLib™VSLib provides deformable modeling as part of a library using the constrained optimization techniques of the calculus of variations. The library supports several very different geometric operations.

PolyMLib™PolyMLib is an object-oriented software toolkit that provides a set of objects and corresponding methods to repair, optimize, review and edit triangle mesh models. It can be used to analyze surface properties, such as smoothness and curvature distribution, as well as to repair and optimize surface meshes.

==History==

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discovered that the people with the best understanding of the presentation were the SDRC representatives. Evidently SDRC was also active in defining a single representation for the standard CAD curves and was working on a similar definition.

So that’s how NURBS started at Boeing. Boehm’s B-spline refinement paper from CAD ’80 was of primary importance. It enabled the staff to understand non-uniform splines and to appreciate the geometrical nature of the definition so as to use B-splines in solving engineering problems. The first use of the geometrical nature of B-splines was in the curve/curve intersection. The Bezier subdivision process was utilized, and a second use was our{{who}} curve offset algorithm, which was based on a polygon offset process that was eventually communicated to and used by SDRC and explained by Tiller and Hanson in their offset paper of 1984. The staff also developed an internal NURBS class taught to about 75 Boeing engineers. The class covered Bezier curves, Bezier to B-spline and surfaces. The first public presentation of our NURBS work was at a Seattle CASA/SME seminar in March 1982. The staff had progressed quite far by then. They could take a rather simple NURBS surface definition of an aircraft and slice it with a plane surface to generate an interesting outline of some of the wing, body and engines. The staff were allowed great freedom in pursuing our ideas and Boeing correctly promoted NURBS, but the task of developing that technology into a usable form was too much for Boeing, which abandoned the TIGER task late in ’84.

For the record, by late 1980, the TIGER Geometry Development Group consisted of Robert Blomgren, Richard Fuhr, George Graf, Peter Kochevar, Eugene Lee, Miriam Lucian and Richard Rice. Robert Blomgren was “lead engineer”. Richard Smith was our supervisor and the manager of the TIGER project was Robert Barnes. As is written at the end of an obituary, “Peace to the memory of TIGER”.

Robert M. Blomgren subsequently formed Applied Geometry in 1984 to commercialize the technology, and Applied Geometry was subsequently purchased by [[Alias Systems Corporation]]/[[Silicon Graphics]]. Solid Modeling Solutions (SMS) was formed in early 1998 by Robert Blomgren and Jim Presti, founded with a commitment to deliver quality products and services with a strong commitment to responsiveness and partnership with our customers. Alliances were developed with GeomWare and IntegrityWare and the non-manifold topology features led to the initial SMLib product in mid-98. A new alliance was established in 1999 with HarmonyWare driven by close collaboration with our customers. This led to IGES, STEP, and VDAFS data translator products in 1999. In late 2001, Nlib was purchased from GeomWare, and the alliance with IntegrityWare was terminated in 2004. Enhancements and major new features are added twice-yearly. SMS is convinced that a small team of talented and motivated experts create better and more efficient products than large corporate projects.

SMS software is based on years of research and application of NURBS technology. Les Piegl and Wayne Tiller (a partner of Solid Modeling Solutions) wrote the definitive "The NURBS Book" on non-uniform rational B-splines (NURBS) with aids to designing geometry for computer-aided environment applications.<ref>Les Piegl & Wayne Tiller: ''The NURBS Book'', Springer 1997</ref> The fundamental mathematics is well defined in this book, and the most faithful manifestation in software is implemented in the SMS product line.

==Philosophy==

SMS provides source code to customers in order to enhance and enable their understanding of the underlying technology, provide opportunities for collaboration, improve time to repair, and protect their investment. The pricing philosophy provides a stable base of technical expertise, and for its customers, reduces the total cost of ownership of complex software.

For reviews of geometry kernels shortly after the first release of SMLib, see Joe Greco's article "Kernel Wars - Episode 1"<ref>"Kernel Wars - Episode 1", Joe Greco, CADENCE magazine, November 1999</ref> and Don LaCourse's article on Geometric Modeling Kernels Revisited".<ref>"Geometric Modeling Kernels Revisited", Don LaCourse, Cadalyst magazine, April 2001</ref> Also, see a recent review of PolyMLib in Desktop Engineering, Nov 2008.<ref>"Polygonal Mesh Library for Postprocessing 3D Scan Data", Desktop Engineering, Nov 2008</ref>

==SMS architecture==

SMLib™SMLib - fully functional non-manifold topological structure and

solid modeling functionality.

TSNLib™TSNLib - analyze NURBS based trimmed surface representations.

GSNLib™GSNLib - based on NLib with curve/curve and surface/surface

intersection capabilities.

NLib™NLib - an advanced geometric modeling kernel based on NURBS

curves and surfaces.

VSLib™VSLib - deformable modeling using the constrained optimization

techniques of the calculus of variations.

PolyMLib™PolyMLib - an object-oriented software toolkit library that

provides a set of objects and corresponding methods

to repair, optimize, review and edit triangle mesh