A scale-invariant shape feature is proposed. The shape feature is extracted on gray voxel models by a SIFT-like algorithm to describe the local shape information of 3D models. Shape feature vectors are constructed by a BoF method. A distance function that supports the part-in-whole matching is employed to compute the dissimilarity between 3D models. Experiments demonstrate that the proposed method achieves a satisfactory retrieval performance.

This paper discusses using 3D model search techniques to build and access case study libraries that act as an interdisciplinary tool for engineering education. After introducing the concept and benefits of managing case study libraries by 3D model search techniques, we present a prototype system of a case study library for mechanical parts development. Several aspects of the prototype system are discussed, including user interface, shape comparison, case browsing and user feedback. The paper ends with some examples of cases retrieved from our library.