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2012/04/13 13:47:56

Geometrical cores (in Russia and the world)

The automation systems of drawing (Computer-Aided Drafting) created in the 1960th for replacement of a drawing table (traditional drawing instrument which architects and engineers of the whole world got used to use since industrial revolution of the 18th century), turned from the automation equipment of routine work into the key tool of innovations in different industries now, having become automation systems of design (Computer-Aided Design).

A modern CAD system allows to solve a set of problems. And a key role is played here by three-dimensional model.[1]


Three-dimensional modeling and virtual reality

In the 1970th the scientists of the whole world working together with representatives of the Defense Ministries and industrial enterprises began to investigate different methods of submission of the three-dimensional data in the computer facilitating the subsequent work with them. Before recent time the three-dimensional model existed only in the heads of designers that created a set of problems and errors — both at design of a product, and by its production, operation and utilization. The experience of the advanced enterprises got in recent years demonstrates that use of three-dimensional digital models of a product at all stages of its lifecycle allows to reduce design costs, to accelerate an output of a new product to the market, to reduce the price of production, to quickly make the changes offered by users to its construction and to reduce harm to the environment to a necessary minimum. Eventually, three-dimensional modeling considerably increases business competitiveness and its capability quickly to react to any changes in economy.

Three-dimensional modeling by this moment has more than 30-year history behind the back. Not all offered ideas were fruitful. Not all developer companies of means of three-dimensional modeling, could endure market perturbations. But the best experience was saved up in the program components called by cores of three-dimensional modeling (3D modeling kernels) which nowadays are the cornerstone almost any CAD (and also CAE and CAM). Developers of engineering software or project such components, code and support independently, or license them at third-party technology suppliers. 3D - the core is the base on which the building of any modern CAD is under construction. All the rest depends on this base — a possibility of different tools, their high-speed performance, resistance to errors, and even the general intellectuality of a system.

From the point of view of the programmer the geometrical core is a library of functions/classes for creation of geometrical objects (a point, a segment/arc/curve, a piece of a surface, a solid body), change of their forms and the sizes, creation on their basis of new objects, visualization of model on the screen of the computer and exchange of three-dimensional data with other programs. Transfer of functions of a core can be pressed down in one offer, but their implementation drags on for tens and hundreds of cheloveko-years. The matter is that behind each elementary transaction (like intersection of two surfaces of the class NURBS) there is a computing algorithm which implementation and debugging is very labor-consuming task requiring both perfect ownership of the device of calculus mathematics, and professional knowledge of data domain. And similar transactions in a core — hundreds (taking into account a variety of types of geometrical data).


NURBS is the main class of surfaces in three-dimensional modeling

Not all developers CAD (and furthermore CAE and CAM) are ready to invest in such volume in a basic technology therefore most of them prefer to license ready 3D - a core at third-party producers (sometimes at the direct competitors), making developer company of a core the regular payments (which are usually including a certain amount from each sold copy of an end product). In exchange they have an opportunity to use a core which was already "rolled" in other systems therefore has rich functionality and the high level of reliability. At last, having taken a ready core, the CAD developer will be able quicker to bring the software product to the market. Sometimes this factor is defining — if to be late with product release for a year - another, then the market can be occupied by competitors. The most striking example is the release of MCAD (Mechanical CAD) of SolidWorks which became the first-ever rule of parametrical solid modeling for the Windows platform and still remaining the absolute leader in the industry of MCAD (machine-building design) in number of the sold licenses. The same way developers of a set of other successful systems went afterwards, including the Russian companies ADEM and Top Systems.


T-FLEX CAD (Top Systems), Parasolid created on the basis of a core

However, in the world of a CAD there is a small amount of the companies which regard as of paramount importance a possibility of full control over the source code, of operational error correction and accumulation of functionality, fast transfer on new platforms and therefore are ready to pay for it with own resources. Belong to this group as top four of the market of a CAD with billion income (Dassault, Autodesk, Siemens and PTC), and the Russian developer ASCON.


KOMPAS-3D (ASCON) created on the basis of own core

Rather complete list of examples of developers, both the first, and second category is given in the table below. From it it is visible that cores of ACIS are most actively licensed (it develops and supported by Spatial, Dassault Systemes subsidiary company) and Parasolid (Siemens PLM Software).

Since 2007. The Government of the Russian Federation performs the federal target program "National Technology Base" for the purpose of creation of new advanced technologies and the equipment, implementation of the developed technologies in production, commercialization of new technologies, creation of a perspective scientific and technology backlog for development of perspective knowledge-intensive products, problem solving of improvement of ecological country situation. Within this program the Ministry of Industry and Trade of the Russian Federation announced the tender for accomplishment of research and developmental work "Creation of the domestic licensed program and mathematical core of three-dimensional modeling as bases for computer systems of automated design of complex machine-building products". Such core, being the basis for new generation of computer systems of design, reverse engineering, preparation of production, creation of technical documentation, will promote creation by the Russian industry of the innovation products competitive in the world market, having become a part of national technology base. The Federal state-funded educational institution of higher education the Moscow state technology university "STANKIN", and one of subcontractors — LEDAS company became the winner of the tender.

The Russian LEDAS company has thirteen years' experience of development knowledge-intensive program the CAD component by request of leaders of the world market of engineering software. Among the projects which are successfully executed by the company — an interval solver for work with engineering knowledge; a solver of geometrical and dimensional restrictions for parametrical drawing, design of assemblies, kinematic animation and direct modeling; modules for work with polygonal grids in real time (conversion of a grid to a surface of division, development of a grid on the plane, calculation of the minimum distances and determination of intersections between grids); modules of broadcast of engineering data. Taking into account the specified experience, the sector of the works connected with algorithm elaboration of calculus and discrete mathematics, and including a problem of high-precision creation of intersection of any surfaces known for the complexity and curves is charged to LEDAS company in the 3D-a core project.

Certainly, when developing new 3D - cores it is necessary to rely on experience of predecessors to take the best of this experience and not to repeat their errors. Therefore we are going to cover in the subsequent publications briefly the history of the previous attempts of creation of cores of three-dimensional modeling and also to tell about in what the Russian core created now will differ from them.

Author: Dmitry Ushakov, Isicad

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Notes