Content Based 3D Shape Retrieval

Recent developments in techniques for modeling, digitizing and visualizing 3D shapes has led to an explosion in the number of available 3D models on the Internet and in domain-specific databases. Currently, large archives recording cultural heritage models like the David of Michelangelo [11], and the Minerva of Arezzo [7] are obtained by laser scanning projects. Also archives containing domain-specific shape models are now accessible on the Internet. Examples are the National Design Repository, an online repository of CAD models, and the Protein Data Bank, an online archive of structural data of biological macromolecules. These developments has led to the design of 3D shape retrieval systems that, given a query object, retrieve similar 3D objects. In visualization, 3D shapes are often represented as a surface, in particular polygonal meshes, for example in VRML format. Often these models contain holes, intersecting polygons, are not manifold, and do not enclose a volume unambiguously. By contrast, 3D volume models, such as solid models produced by CAD systems, or voxels models, enclose a volume properly. Unlike text documents, 3D models are not easily retrieved. Attempting to find a 3D model using textual annotation and a conventional text-based search engine would not work in many cases. The annotations added by human beings depend on language, culture, age, sex, and other factors. They may be too limited or ambiguous. In contrast, content based 3D shape retrieval methods, that use shape properties of the 3D models to search for similar models, work better than text based methods [14]. In content based shape retrieval, the following terminology is often used. Shape matching is the process of determining how similar two shapes are. This is often done by computing a distance. A complementary process is indexing. Here, indexing is understood to be the process of building a datastructure to speed up the search. Note that also " indexing " is also used as a term for the identification of features in models, or multimedia documents in general. Retrieval is the process of searching and delivering the query results. Matching and indexing are often part of the retrieval process. Recently, a lot of researchers have investigated the specific problem of content based 3D shape retrieval. Also, an extensive amount of literature can be found in the related fields of computer vision, object recognition, geometric modeling, computer-aided design and engineering. Survey papers to this literature have been provided by Besl and Jain …