About LGS 3D                  About LGS 2D

The LGS 3D geometric constraint solver, developed and supported by LEDAS since 2004, is offered for licensing to all CAD/CAM/CAE software development companies at an affordable price. It is commonly used as parametric engine for direct modeling of 3D geometry, assembly design, motion analysis, and other 3D geometric modeling applications. LGS 3D is a cross-platform software packages running on 32- and 64-bit versions of Windows, Linux, Mac OS X, *BSD, AIX, HP-UX, Sun Solaris, and other OSes. Coded in C++, LGS 3D has a C-style API for easy integration into a broad range of software applications using a variety of wrappers, such as .NET, Java, and C++.

LGS 3D supports the creation and modification of geometric models by means of explicit or implicit constraints. (Geometric objects include points, lines, circles, planes, cylinders, spheres, cones, tori, parametric curves, surfaces and swept surfaces.) Objects can be fixed in the absolute coordinate system or relative to each other. Supported geometric constraints include logical constraints between geometric entities (coincidence, parallelism, tangency, and so on), and dimensional constraints that specify the required values for distances, angles, or radiuses. LGS 3D moves and rotates objects to positions that satisfy all constraints, yet minimizes transformations from the initial configuration. Other LGS functions implement advanced features of CAD/CAM/CAE systems, such as diagnostics of over- and under-defined parts of models, engineering variables and equations, help points, and tolerance management.

Sample application named Lege’n’d 3D is available for free download from the LEDAS Web site. It is bundled with a set of representative examples of different kinds of 3D assemblies. The application can be used by anyone to test the functionality, robustness, and performance of LGS 3D. Lege’n’d 3D was created with the Open CASCADE open-source application framework, and its source code is available to all licensees of LGS 3D.

Current version is LGS 3D 5.0 (released in April 2011)

Version 5.0 improves LGS 3D performance, introduces several new functions requested by LEDAS customers, and enhances the quality of the solutions.

The move-under-constraints function allows users to drag one or more geometric objects interactively, while LGS 3D solves the constraints dynamically at each intermediate step. This makes it easy for users to adjust their designs, and to explore the kinematics of complex mechanisms. The new algorithm for adaptive calculation of move-under-constraints in LGS 3D 5.0 speeds up this function by 100%, on average.

LGS 3D can deal with inconsistent problems, and with version 5.0 inconsistent models are processed 30% faster on average, thanks to minimizing of the number of iterations to solve.

In some design contexts, users need to know whether a particular constraint is satisfied. In previous releases, the only way to do this was to run the LGS 3D solver procedure, which proved to be time-consuming for large models. Version 5.0 introduces new functions that very quickly check if one or all constraints are satisfied.

The scope of some problem decomposition and heuristic methods has been extended to support models with non-rigid objects and variables.

The DOF (degrees of freedom) analysis introduced with the previous version of LGS 3D has been improved in version 5.0. The number of spiraling DOFs is minimized whenever possible. LEDAS developers also eliminated several bugs reported by customers.

New version of LGS 3D is already embedded in several applications, including a recent first commercial release of the RhinoWorks plug-in for McNeel & Associates’ Rhinoceros 3D modeling software. RhinoWorks, as a part of the Driving Dimensions product line, aims at making advanced mechanical CAD technology available to all users of popular 3D software at an affordable price. For more information, please visit www.DrivingDimensions.com.

For the full list of changes see Release Status page.