Surface Reconstruction of Freeform Objects Based on Multiresolution Volumetric Method for Distributed CAD

Abstract

Reverse engineering processes have recently become an essential part of distributed design systems. This is particularly relevant when no CAD model is available so the physical model is used as a base for the design. This paper describes a new and fast reverse engineering method for creating a 3D computerized model from a cloud of points sampled from an object’s boundary. The proposed method aggregates large-scale 3D scanned data into a Hierarchical Space Decomposition Model (HSDM), realized by the Octree data structure. This model can represent both the boundary surface and the interior volume of an object. Based on the proposed volumetric model, the boundary reconstruction process becomes more robust and stable with respect to sampling noise. The hierarchical structure of the proposed volumetric model enables data reduction, while preserving sharp geometrical features and object topology. As a result of data reduction, the computation time of the reconstruction process is significantly reduced. Moreover, the proposed model naturally allows multiresolution boundary extraction, represented by a mesh with regular properties. This representation is highly suitable for a distributed CAD environment, where it can facilitate reconstruction, rendering and modeling performance. The proposed surface reconstruction approach is based on Connectivity Graph (CG) extraction from HSDM, and facet reconstruction. This method’s feasibility will be presented on a number of complex objects.