Discover new business dimensions with LEDAS three-dimensional geometric solver LGS 3D

Ledas releases the first commercial version of its three-dimensional Geometric Solver LGS 3D, a software component for 3D parametric variational design used for development of modern CAD/CAM/CAE applications. It will be the forth available version in the family of the solvers developed on the basis of Ledas computational engine. The first LGS versions are LGS 2D Light, LGS 2D Extended and LGS 2D Advanced are for two dimensional sketching, and new three dimensional Geometric Solver is a breakthrough in the line of the Ledas products and new opportunities for the Ledas' customers.

In the beginning of the 2004 Ledas announced the release of its two dimensional geometric solver LGS 2D. So far tens of requests have been processed from a wide variety of the CAD/CAM/CAE development companies having their businesses within building construction, furniture designing, aerospace industry, reverse engineering, manufacturing of construction and mining equipment and academic research institutes and universities worldwide. A number of the requesters already use LGS 2D as an integral part of the development works in frameworks of the long term license agreements with Ledas.

Ledas three-dimensional geometric solver significantly expands the possibilities to apply computational engine. It supports creation and modification of the 3D geometric models. In general, three-dimensional solvers are for the similar purposes as two dimensional ones - they allow the users to define the constraints on the three dimensional objects and modify 3D models correspondingly. The set of three-dimensional objects and constraints intersect with the analogous set in two dimensional case. The three dimensional objects are represented by points, lines, planes, curves, surfaces and rigid sets constructed from them. The constraints which could be defined on the objects are fixation, coincidence, concentricity, distance, angle and planar angle, perpendicularity and parallelism, tangency. The same is valid for the functions: placing of the objects in correspondence to the defined on them constraints, moving and rotating the objects, identification of the over-defined objects are the same as in two-dimensional case.

Nevertheless, the application area for three dimensional solvers (and it is why the solvers are usually vary and are different software libraries) is assembly of the mechanisms and their parts. The constraints in this case play role of the real assembly constraints and functionality of the 3D solver is defined in many respects by modeling of the assembly. In such a way, the main role belongs to the rigid sets in three-dimensional case - in fact the primitives are used to construct the rigid sets whereas the constraints are mainly used to define the disposition between the mechanism's parts. Typical problems of assembly design which can be solved with the 3D solver are positioning rigid parts with respect to given set of constraints and moving the parts dynamically keeping all constraints satisfied. LGS 3D solves these problems efficiently providing the most natural of possible solutions or - in case of inconsistent problem - detects which constraints are contradictory. Other CAD/CAM/CAE applications for LGS 3D include feature-based part design (where LGS 3D can be used to position the features with respect to each other), surface design (where LGS 3D can be used to position control points and curves), and kinematics (where LGS 3D can be used to solve direct and inverse kinematics problem).

The commercial release of the LGS 3D concludes started in November, 2004 Early Access Program for Ledas Geometric Solver (LGS 3D EAP). Ledas appreciates all received comments and suggestions from the registered EAP participants. From now the customers' requests for LGS 3D evaluation (LGS 3D, sample test application for LGS 3D called Lege'n'd 3D, and the related documentations) will be processed by Sales and Marketing Department on individual basis. The applications should be sent to To get more information about related to LGS 3D issues please visit the dedicated website

LGS 3D is based on the Ledas' state-of-the-art engine developed for those who need a strong variational and constraint-based functionality in CAD, modeling, or engineering software.

Through the scalable architecture of LGS, variational and parametric techniques can become available in a wide range of the products including desktop CAD and object modeling tools. High-end CAD and CAM systems will also benefit from integration with LGS since it provides a solid foundation for variational modeling, knowledge-based engineering, constraint-based geometry, and mechanical optimizations.

About LGS 3D

LGS 3D is a C++ class library that runs under Windows 2000 and XP (versions for Linux, FreeBSD, and AIX platforms are available under request). It can be integrated (via its API written in C) into a broad range of software applications. A sample test application for LGS 3D called Lege'n'd 3D is also available within the Evaluation version of LGS 3D. It was created with the Open CASCADE open-source framework. The Lege'n'd 3D application can be used to test the entire functionality of the LGS 3D without any integration of the solver into other software packages. A set of representative examples for Lege'n'd 3D is also supplied.

LEDAS Geometric Solver 3D supports creation and modification of the geometric models by means of (explicit or implicit) constraints. Typical geometric objects are points, lines, circles, planes, cylinders, spheres, arbitrary curves, surfaces and swept surfaces. Objects can be fixed in an absolute coordinate system or with respect to each other (last feature is provided by so-called rigid sets of objects). Set of geometric constraints includes logical constraints between geometric entities (like coincidence, parallelism, tangency, etc.), dimensional constraints (that specify the required values for given distances, angles, radii). LGS 3D moves and rotates objects to positions where all constraints are satisfied trying to perform minimal possible transformations of initial configuration. Other functions are usual for CAD - 'move under constraints' and diagnostics of over- and under-defined parts of a model. The version 1.0 supports advanced features like engineering equations and help points.


LEDAS Ltd. is an independent software company founded in 1999 and located in Novosibirsk, Russia. LEDAS developed a state-of-the-art proprietary technology based on constraint programming, and applies it to PLM (Product Lifecycle Management) tasks, including CAD/CAM domain, for resource and project scheduling. Information on LEDAS is available on the Internet at:

Windows is a registered trademark of Microsoft Corporation in the United States and other countries. Linux is a registered trademark of Linus Torvalds. FreeBSD is a registered trademark of Wind River Systems, Inc. AIX is a registered trademark of International Business Machines Corporation. Open CASCADE is a registered trademark of Open CASCADE S.A.


Alexey Rasskazov
Tel: +7 383 3356 504
Fax: +7 383 3356 256