LEDAS Launches First Release of its 2D Geometric Solver Solution LGS and Announces Forthcoming 3D Geometric Solver

LEDAS Ltd. announced today the general availability of LGS (LEDAS Geometric Solver) Version 1.0, its two-dimensional computation engine that supports creation and modification of designs using geometric and engineering constraints in CAD/CAM/CAE/PLM solutions. This new, state-of-the-art engine can be used by application developers who need strong variational and constraint-based functionality in CAD, modeling, or engineering software.

Variational modeling is now standard in most high-end mechanical CAD applications. Through the scalable architecture of LGS, variational and parametric techniques can become available in a wide range of products including desktop CAD and modeling tools, architectural software, virtual-reality scene and object modeling tools, publishing software, and many more. However, LGS with its strong computation and optimization algorithms can benefit high-end CAD and CAM systems as well, providing a solid foundation for variational modeling, knowledge-based engineering, constraint-based geometry, and mechanical optimizations.

The pre-release version of LGS 2D was first made available in April 2003, when LEDAS launched the LGS Early Access Program. The first available LGS Version 0.3 supported only points, lines, and circles of fixed radii with simple constraints over them, such as incidence, distance, and angle. Since then, the following major improvements were made:

  • a large set of additional supported objects (including circles of variable radii, ellipses, user-defined curves, and rigid sets),
  • new types of constraints (radius, equal distances and radii, mid point, tangency, horizontal and vertical distances, dependency),
  • help parameters for tangency and incidence constraints containing curves,
  • ability to solve overconstrained but consistent cases,
  • overdefined diagnostics,
  • partial solution for inconsistent cases,
  • simplification of the LGS API,
  • improving the quality and performance, naturalness of behavior, scalability and flexibility (the 2D LGS has been tested on thousands of test problems, including both real-world examples and automatically generated, synthetic cases).

Proposed future enhancements to the 2D LGS include (the list is subject to change):

  • full support for splines,
  • well-constrained diagnostics,
  • move-under-constraints,
  • auto-constraining,
  • user-defined engineering constraints,
  • optimization algorithms.

In parallel, LEDAS initiated the development of the 3D version of LGS, with the first prerelease scheduled for the third quarter of 2004. It will include support for all 3D entities (both objects and constraints) together with fullrange functionality across them (general update, overdefined diagnostics, partial solution, move under constraints).

LGS is a C++ class library that runs on Windows 2000 and XP, Linux, FreeBSD, and AIX platforms. It can be integrated (via its API written in C) into any kind of software applications. A sample test application for LGS called Lege’n’d is available for free download at the LEDAS web-site. It was created with the Open CASCADE open-source framework. The Lege’n’d application can be used to test the entire functionality of the 2D LGS. A set of representative examples for Lege’n’d is also freely downloadable.

In June 2004 in Novosibirsk, Russia, in the framework of the isiCAD-2004 International Workshop, LEDAS will present the 2D LGS solution before an audience including representatives of international and Russian CAD development companies.


LEDAS Ltd. is a private 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 for PLM (Product Lifecycle Management) tasks, including CAD/CAM domain. Information on LEDAS is available on the Internet at: ledas.com

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.