Reverse Engineering of CAD Models

Here we consider polygonal meshes of mechanical objects and extract 2D and 3D features of those objects. 2D features include all sharp boundary corners of the object and 3D features include surfaces that make up curved parts of the object. We are specifically dealing with triangle meshes obtained either from scanners or generated procedurally by other software applications. Techniques we have implemented are generic and are applicable for other types of polygonal meshes also.

Significance of our approach is in usage of Discrete Differential Geometry. Two discrete curvature measurements, Gauss Curvature and Integrated Mean Curvature are calculated at basic entities of the mesh: vertices and edges. Measurements at these entities are utilized in extracting edges at sharp corners and facets on curved surfaces, resulting in 2D and 3D features, respectively.

Nature of the Project

Knowledge Transfer Partnership (KTP) is a scheme sponsored by the Department of Trade and Industry, UK where academic institutions and industries collaborate together. Industries seek input of academic knowledge in developing high quality products and increase their market size. For this, a KTP Associate is employed who will be mainly based at the industry. The Associate is responsible for managing the project and acting as a bridge between academic institution and the industry. He/She will also be provided with huge resources for their personal development.

Academic partner in this case is UCL and Vero is the Industrial Collaborator.

Vero UK Ltd.

Vero UK Ltd., is a CAD/CAM software development company with its head-office based in Stroud, Gloucestershire. It has branches in Italy, France, USA, Canada, China and Japan. Company develops, owns and markets a variety number of software tools and products which are used in manufacturing industries, automobile industries and in a variety of other engineering industries. Full details on company's line of tools and products.

Result of this project

We are half-way through the project and we have achieved extraction of 2D and 3D features of the objects, although fitting surfaces to extracted 3D shapes is still remaining; which is a significant part. The tool will become a part of Vero's standard CAD package VISI^® and is expected to be launched for commercial usage in the upcoming release.

Some sample images below depict our up-to-date work.