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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™ 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.<ref>Polygonal Mesh Library for Postprocessing 3D Scan Data, Desktop Engineering, Nov 2008</ref>
== History ==
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P(t) = ∑iwiPibi(t) / ∑iwibi(t)
for anything more than a conic Bezier segment. Searching for a single form, the group worked together, learning about knots, multiple knots and how nicely Bezier segments, especially the conics, could be imbedded into a B-spline curve with multiple knots. Looking back, it seemed so simple: It is easy to verify that the equation for P(t) is valid for the B-spline basis functions as well as for Bernstein basis functions. By the end of 1980 the staff knew we had a way to present all the required curve forms using a single representation, now know as the NURBS form. But this new representation could easily have died at this point. The staff were already 12 to 18 months down a development path. They had completed a large number of algorithms using the old curve forms. They now had to convince our managers and the other technical groups, such as the database and graphics groups, that they should be allowed to start over using a single representation for all curves. The NURBS surface form did not present a problem since they had not yet developed any surface algorithms. The review of this new TIGER curve form was held on February 13, 1981. The review was successful and the staff were allowed to start over using the new curve form. It was at this time that the NURBS acronym was first used by the other side of the TIGER project, i.e., the TIGER software development groups of Boeing Computer Services. Management was very eager to promote the use of these new curve and surface forms. They had a limited understanding of the mathematics but they were very aware of the need to communicate geometric data between systems. Hence, Boeing very quickly prepared to propose NURBS to the August ’81 [[IGES]] meetings. Richard Fuhr, of our group, was assigned the job of presenting NURBS to IGES. His presentation was very well received and shortly afterwards he put together the Boeing document which was distributed to many IGES members.
There are two reasons why NURBS were so quickly accepted by IGES. The first was that IGES was in great need of a way to represent objects. Up to that point there were, for example, only two surface definitions in IGES and the B-spline form was restricted to cubic splines. The other, surprisingly important, reason for the rapid acceptance was that Boeing, not being a CAD system supplier, was not a threat to any of the major turnkey system vendors. Evidently, IGES easily bogs down when different vendors support their own slightly different representations for the same objects. At this first IGES meeting, it was
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 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 of 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 useable 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 is committed to providing 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. Web-based delivery of product delivery, maintenance, and communication has enabled SMS to be extremely responsive, among the best in the industry. SMS has no underlying debt, no hidden partners, and is totally employee owned. SMS is independent of any proprietary influences and totally committed to an open and responsive relationship with its customer base. SMS has established a very unique model of technical organization and an adaptive open-source approach. The pricing philosophy provides a stable base of technical expertise, and it is very cost-effective for its customers when viewed from the perspective of total cost of ownership of complex software. A license for an SMS product represents a fraction of what it would cost to develop and maintain the same capability in-house.<ref>"Kernel Wars - Episode 1", Joe Greco, CADENCE magazine, November 1999</ref>
Recent customer comments include: "SMLib looks to be very interesting. I'm especially attracted by the fact that it is distributed in source code form. I hate opaque black boxes! Also the licensing terms seem to fit our needs."; "Gotta love source code, and the VC++ debugger! This problem only slowed me down for 5 minutes, whereas if this was an object library it would have been a week in the very best circumstances."; With respect to SMLib selection as one of the "Top 10 Software for 1998" by IEEE Computer & Graphics Applications, one of our customers said: "Congratulations! It's certainly one of my personal top 10."; "In my opinion, the quality of the code is excellent - world class..."; "...the support is nothing less than phenomenal. "; and from a major software developer regarding geometry kernel independence: "The destiny of software developers that stick with ACIS or Parasolid will be inextricably linked to Dassault or Unigraphics. Any competitor posing risk to either company could put itself in jeopardy of delays in receiving updates, bug fixes, and contract renewals."<ref>"Geometric Modeling Kernels Revisited", Don LaCourse, Cadalyst magazine, April 2001</ref>
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