Reverse engineering aims at reproducing an existing object by analysing its dimensions, features, form, and properties. The collected data and information m ust be transform ed into pertinent product knowledge at various levels of detail. In reverse engineering research, emphasis has been placed on recovering the general form or the product functions. For the form recovery tasks, existing techniques focus on creating com puter aided design (CAD) surface models from point cloud data collected from scanning systems. This model is mathematically ‘exact’, but may be inaccurate due to noise contained in the model. As well, the surfaces and edges in the resulting CAD model have no functional meaning, which is inappropriate for mechanical components. The functional related tasks focus on establishing the component’s functional requirements and its relationship within the product. For effective design recovery, these aspects must be combined and expanded upon at various levels of granularity. To meet these challenges, a systematic approach is adopted in a comprehensive manner to extract the relevant information and transform it into pertinent design knowledge. A modular design recovery framework is presented that captures the component’s structure, function and feature information at varying perspectives. An integrated approach that assesses the component from different perspectives in an innovative manner leads to a more complete model, as no one perspective or set of tools can provide a complete, comprehensive engineering representation. The design recovery framework can be leveraged to assess or improve the product design using other design methodologies and tools.

To complement the framework, form recovery algorithms have been developed to transform point cloud data into wire frame geometry consisting of standard line and arc elements. Once the points are converted into curve primitives, adjustments are made to capture the design intent using heuristics, and common shapes and 2D patterns are detected. From this geometry, a surface or solid model can be constructed using established geometry creation tools. Several practical case studies are presented that illustrate the application of the design recovery framework and highlight its merits.