Building Editable B-rep Models from Unorganized Point Clouds

We present a novel integrated approach to reverse engineering point clouds by producing fully editable feature-based Boundary Representation (B-rep) models. We use point cloud morphology analysis techniques to extract features from a 3D point cloud. We then reconstruct the boundary contours of features using a fast and efficient fitting approach employing a sequence of piecewise rational Bezier curves that are G continuous. We introduce a technique for reconstructing the features derived from the point cloud using solid modeling techniques, such as sweeping, skinning and covering, providing editability and model re-design capability. The solid modeling techniques selected for feature reconstruction depend on the morphology of the point set and the complexity of the reconstructed contours of the feature. We support parameter definition on each feature to render attributes such as construction techniques, adjacency and other topological characteristics. A feature connectivity graph is derived and used for producing a feature assembly plan that describes the reconstruction process of the Brep model. Interand intrafeature constraints are imposed to ensure that the final reconstructed model is editable, robust and accurate. We offer examples of using our reengineering system to demonstrate the feasibility of this method and its unique editing capabilities.