Geometric Engine
NURBS are the de-facto standard in the representation and data exchange between commercial systems for geometrical and solid modeling. However, since they are limited in the representation of arbitrary topology surfaces, research activity of the WP 1 is oriented toward a new emerging class of surfaces, subdivision surfaces, that, although similar in characteristics and advantages, could offer a promising alternative. Subdivision surfaces are defined as the limit of a sequence of successive refinements appllied to a starting polygon or mesh and, since no constraints on the shape or topology of the starting mesh are given, subdivision surfaces allow the modeling of objects with very complex shape in a simple and natural way. Thanks to theses characteristics, they have been widely used in the digital animation and gaming industry but some unresolved problems still prevent the diffusion and use of subdivision surfaces in CAD systems.
Research efforts of the WP1 are divided into two main objectives:
- Geometric Engine for CAD system: implementation of a plug-in software for a commercial CAD system, integrating subdivision curves and surface as modeling primitives in the geometric kernel, to put side by side with the well-established NURBS. The prototype is used to demonstrate this design process: subdivision surfaces as a flexible shape definition tool.
- Innovative subdivision schemes : design of new subdivision schemes able to generate surfaces satisfying the CAD requirements such as C2 continuity, parametricability, good surface quality and exact evaluation at parametric domain values.