Jul 5: LEDAS Adds Advanced Parametric Drawing Functions to Version 4.0 of its 2D Constraint Solver
Patterns, directed distances, and orientation/alignment attributes help
users of CAD/CAM/CAE applications to fully control constrained drawings
Novosibirsk, Russia, July 5, 2010 – LEDAS Ltd., the independent provider of
constraint-based design tools, component technologies, and software
development services for the CAD/CAM/CAE/PLM market, today announced version
4.0 of LGS 2D, its geometric constraint solver. As a core component of
parametric drawing applications, LGS 2D allows users to express design
intent through geometric and dimensional constraints applied to elements of
sketches and drawings.
New Features in LGS 2D 4.0
Version 4.0 of LGS 2D introduces the following new functions: linear pattern
constraints, directed distance constraints, and alignment/orientation
attributes for most constraints.
Linear pattern constraints set relations between several sub-geometries of
equal shapes (e.g. rectangles), aligning and uniformly distributing them
along a given direction. Any changes in position or orientation of any one
of the pattern constraint’s arguments leads to corresponding changes in
other arguments. As with other LGS 2D constraints, a linear pattern
constraint is variational, which means it can be combined with other
constraints that are imposed on pattern’s sub-geometries. All constraints
are solved simultaneously.
Alignment attributes specify whether the tangent vectors of the constraint
arguments are co-directed (collinear vectors with positive scalar product)
or counter-directed (collinear vectors with negative scalar product). The
attribute can be applied to any constraint involving two non-point entities:
tangency, distance, parallelism, or perpendicularity between lines, circles,
curves or ellipses.
Orientation attributes control whether an argument is positioned to the left
or right side of other ones. They are applied to all distance constraints,
except point-point distances. Orientation and alignment attributes fully
control the chirality (left or right handedness) of constraints.
For developers, LEDAS provides special integration facilities that simplify
the job of embedding LGS 2D into their applications. In particular, all
members of Open Design Alliance can use the LGS 2D integration module
(developed jointly by LEDAS and the ODA) to quickly implement constraint
drawing functions that are fully compatible with the DWG file format. The
ODA is a non-profit organization that develops the Teigha™ (formerly
DWGdirect) software development platform for CAD and other technical
“The new functions in version 4 were ones requested by our customers,” said
Dmitry Ushakov, Director of Product Management at LEDAS. “Our customers’
satisfaction with our products is the greatest recognition we can receive.
We appreciate their feedback on our components so that we can continue to
About LGS Software
Since their first commercial release in 2004, the LGS 2D/3D software
components have been licensed by a dozen CAD/CAM/CAE vendors, who have
embedded them into their applications successfully.
The LGS 2D and 3D geometric constraint solvers are used as parametric
engines for 2D sketching and drawing, history-free 3D modeling, assembly
design, motion analysis, and other applications. LGS 2D/3D are
cross-platform software packages running on 32- and 64-bit versions of
Windows, Linux, Mac OS X, *BSD, AIX, HP-UX, and other operating systems. LGS
2D/3D have 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 2D/3D supports the creation and modification of geometric models by
means of explicit and implicit constraints. Geometric objects that can be
constrained include points, lines, circles, ellipses, planes, cylinders,
spheres, NURBS, and application-defined parametric curves, and surfaces.
Objects can be fixed in the absolute coordinate system or relative to each
other. Supported constraints include geometric relations between objects
(coincidence, parallelism, tangency, and so on) and dimensions that specify
the required values for distances, angles, and radii. LGS 2D/3D moves and
rotates objects to positions that satisfy all constraints, yet minimizes
transformations from initial configurations.
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.
Example applications called “Lege’n’d 2D/3D” are available as free downloads
from the LEDAS web site. Provided with a collection of sample models
representing different kinds of 2D sketches and 3D assemblies, the
applications can be used to test the functionality, robustness, and
performance of LGS 2D/3D. The sample applications were created with the Open
CASCADE open-source application framework; the source code is available to
To learn more about LGS 2D/3D, visit the LEDAS Web site at
LEDAS Ltd. is an independent software development company founded in 1999.
It is based in the Novosibirsk Scientific Centre of the Siberian Branch of
the Russian Academy of Science. A leader in constraint-based technologies,
LEDAS is a well-known provider of computational software components for PLM
(Product Lifecycle Management) solutions: geometric constraint solvers for
CAD/CAM/CAE, optimization engines for project management, work scheduling,
and meeting planning, as well as interval technologies for knowledge-based
engineering and collaborative design. The company also provides
comprehensive services for PLM markets, including custom software
development and consulting. More information about LEDAS is available at
LGS is a trademark of LEDAS Ltd. Any other trademarks are the property of
their respective owners.