Technology

Driving Dimensions plug-ins allow you to modify any 3D geometry easily. Just add linear, radial or angular dimension between geometric elements of your model (faces, edges, vertices) and type in a desired value: your geometry will be automatically arranged. Moreover, all dimensions, which were set previously, are taking into account when you add a new dimension. It allows you to specify desired behavior when a particular dimension is changed. Engineers call such specifications design intent.

Driving Dimensions software is based on Variational Direct Modeling, a powerful technology for easy parametric modification of 3D solid, surface and wireframe models in history-free environment with automatic recognition of design intent. It combines direct modeling with a constraint-based approach, from which we get "variational". The technology places a direct modeling system at the level of a parametric (a.k.a. history-based) one -- yet for end users retains the simplicity of direct modeling operations.

In CAD, constraints are primarily used in 2D designs with parametric sketches, and in 3D with assemblies. (The design of parts, however, is still managed through history-based trees.) The problem with applying constraints during solid/surface modeling lies in its complexity. The solution involves determining implicit topological and geometric relations between the faces, edges, and vertices of boundary models. This is achieved by employing a fast, robust constraint solver.

Another challenge lies in the ability of the CAD system to recognize design intent in any form of dumb geometry automatically, and then to express it as sets of constraints, which are consistent and contain no redundancy.

Our VDM technology overcomes both problems, and has been successfully implemented as a plug-in for two prominent CAD systems -- SketchUp and Rhino. Because it outperforms direct modeling in intelligence and history-based modeling in flexibility, VDM is able to replace existing CAD technologies. We foresee the significance that of the potential that this technology holds for users of all popular MCAD and AEC CAD systems. Our VDM technology is now changing the way users work with history-free geometry, making it neither dumb nor stupid anymore.