At a glance

To briefly demonstrate LGS 3D, here we propose to consider its implementation in Lege'n'd 3D System. The Lege'n'd 3D is provided in framework of the LGS 3D demonstration and its version is available within download section of the LGS 3D site. This version allows LGS 3D potential customers to easily evaluate the LGS 3D package: import/export models of a predefined format like IGES and STEP from/to CAD packages; define constraints and satisfy them in case of existence of a solution.

The realization of the aforesaid is demonstrated on the pictures above for the model of a hinge. In particular, one can use such common CAD features like

• save/restore model;
• zooming and panning;
• using object and constraint tree;
• using "quick constraint" feature;
• immediate interrupting of calculation;
• moving objects and changing constraint parameters.

The current version of the LGS 3D supports the following types of objects:

• points
• lines
• planes
• circles
• cylinders
• spheres
• cones
• tori
• parametric (or user-defined) curves and surfaces
• swept surfaces
• variables

A wider set of geometrical objects can be easily modeled with the help of constraints: for example, in order to create a line segment, an application can use a line, 2 points and 2 coincidence constraints. To model more complex parts, a rigid set feature can be used. It allows one to define a set of objects as a rigid body. All objects included in a rigid set are moved and rotated altogether, while their relative positions within the body are preserved.

The LGS 3D supports the following types of constraints:

• coincidence
• fixation
• distance
• angle
• tangency
• perpendicularity
• parallelism
• concentricity
• equations for variables

The most usual application of a 3-dimensional variational solver is assembling a whole mechanism from its parts. Namely, a user, with the help of tools for creating solid 3D models, designs each part of his product. Then he generates the assembly constraints that state how these parts relate to each other. The constraints can leave some degrees of freedom, which will be the degrees of freedom of the final mechanism. When all constraints are generated, LGS 3D is launched and the product is gathered from its parts with respect to all constraints applied. A simple assembly model is shown in the provided examples.