Comparing 3D CAD Models: Uses, Methods, Tools and Perspectives

Abstract

With the advancements of 3D modeling software, the use of 3D CAD in mechanical product design has become a standard practice. Methods and tools are continually being developed to improve designers' efficiency in the creation, modification and analysis of 3D CAD models. Among other advantages, comparing 3D CAD models to assess their relative shape similarity or to identify their differences leads to benefits in various CAD-and PLM-related areas such as design reuse, engineering change management and data exchange. As 3D data continues to be more frequently and intensively shared and used in the mechanical product development process (PDP), this paper describes the subject of 3D CAD model comparison from three related points of view. First, it organizes the wide variety of use cases for 3D CAD model comparison into specific application domains. Difference calculation methods and approaches are compared, identifying their key characteristics and limitations. Then, it presents an inventory of commercially available software tools that perform 3D CAD model difference identification (MDI). Finally, some research perspectives for 3D CAD model comparison applied to shape change transposition are contemplated.

Integration of Explicit Geometric Constraints in the Comparison of 3D CAD Models for Part Design Reuse

“…A number of 3D CAD model difference calculation techniques were surveyed and detailed in [7]. It has been observed, most notably in commercial software, that 3D CAD model difference representation is often eclipsed by visualization schemes prematurely focused on displaying unrefined geometric calculation results.…”

“…[2,3]). However, like other design retrieval methodologies such as function-based [4] or case-based retrieval [5], shape-based retrieval only contributes to the overall part design reuse problem as an opening step [6,7]. As pictured in Fig.…”

“…In 3D CAD model comparison, model difference identification (MDI) distinguishes itself from shape similarity assessment mainly in the level of details revealed by the comparison results [7]. Similarity assessment generally exploits highly abstracted or reduced geometric model contents, generally referred to as shape signatures [1], to produce quick diagnoses on two shapes' equivalence ("yes" or "no") or relative similarity (a qualitative, scale-based measure).…”

Thin part identification for CAD model classification

“…Even if the problem of shape similarity analysis has been already faced in the CAD/PLM field to solve different problems, the efficient information retrieval is still considered a big challenge in most of the manufacturing companies. In Brière-Côté et al (2012), a survey on the application usage of CAD model comparison is presented and put in correspondence with the solution approaches adopted, namely shape retrieval, similarity assessment and difference identification. Shape similarity and retrieval in CAD/PLM are exploited to reuse product information, in CAD models' management to avoid part duplication, to verify data translation, to manage changes and for product rationalization and standardization.…”

“…Various shape matching methods exist (Tangelder and Veltkamp, 2008;Cardone et al, 2003;Iyer et al, 2005;Li et al, 2010;Brière-Côté et al, 2012;Demirci et al, 2008;Zhu et al, 2012;Ohbuchi et al, 2005) and can be classified in three main categories: feature-based methods, graph-based methods and geometry-based methods (Figure 2). These methods have been implemented and tested and the results are more or less efficient but only when trying to retrieve a shape which is similar to the one of the query from the point of view of form and structure.…”