As the number of 3D models available on the Web grows, there is an increasing need for a search engine to help people find them. Unfortunately, traditional text-based search techniques are not always effective for 3D data. In this article, we investigate new shape-based search methods. The key challenges are to develop query methods simple enough for novice users and matching algorithms robust enough to work for arbitrary polygonal models. We present a Web-based search engine system that supports queries based on 3D sketches, 2D sketches, 3D models, and/or text keywords. For the shape-based queries, we have developed a new matching algorithm that uses spherical harmonics to compute discriminating similarity measures without requiring repair of model degeneracies or alignment of orientations. It provides 46 to 245p better performance than related shape-matching methods during precision--recall experiments, and it is fast enough to return query results from a repository of 20,000 models in under a second. The net result is a growing interactive index of 3D models available on the Web (i.e., a Google for 3D models).

A search engine for 3D models

Three-dimensional shape searching is a problem of current interest in several different fields. Most techniques have been developed for a particular domain and reduce a shape into a simpler shape representation. The techniques developed for a particular domain will also find applications in other domains. We classify and compare various 3D shape searching techniques based on their shape representations. A brief description of each technique is provided followed by a detailed survey of the state-of-the-art. The paper concludes by identifying gaps in current shape search techniques and identifies directions for future research.

https://engineering.purdue.edu/PRECISE/Publications/ThreeDimensionalShapeSearchingStateoftheartReviewan/review_shape.pdf

Three-dimensional shape searching: state-of-the-art review and future trends

Three-dimensional shape retrieval is a problem of current interest in several different fields, especially in the mechanical engineering domain. There exists a large body of work in developing representations for 3D shapes. However, there has been limited work done in developing domain-dependent benchmark databases for 3D shape searching. We propose a benchmark database for evaluating shape-based search methods relevant to the mechanical engineering domain. Twelve different shape descriptors belonging to three categories, namely: (1) feature vector-based, (2) histogram-based, and (3) view-based, are compared using the benchmark database. The main contributions of this paper are the development of a new engineering shape benchmark and an understanding of the effectiveness of different shape representations for classes of engineering parts. Overall, it was found that view-based representations yielded better retrieval results for a majority of shape classes, while no single method performed best for all shape categories.

/pdf/developing-an-engineering-shape-benchmark-for-cad-models-4nelqeo4mq.pdf

Developing an engineering shape benchmark for CAD models

The present invention relates to methods and devices for analyzing x-ray images. In particular, devices, methods and algorithms are provided that allow for the accurate and reliable evaluation of bone structure and macro-anatomical parameters from x-ray images.

Methods for the Compensation of Imaging Technique In The Processing of Radiographic Images

A user of a virtual object or computer model uses a haptic interface device in the real world to manipulate a virtual tool in a virtual environment to interact and modify the virtual object. The user uses the virtual tool in a sculpting mode to modify the shape of the virtual object by adding, removing, or modifying the material of the object. The user feels an interaction force from the virtual tool as it interacts with and modifies the virtual object. The designer can set geometric constraints, such as a constraint point, constraint line, or constraint surface, to limit or guide the movement of the virtual tool.

Systems and methods for sculpting virtual objects in a haptic virtual reality environment

A computer system (100) and method for the storage, archiving, query and retrieval of information relating to 3D objects is provided. The systeme includes data acquisition (130) means for requiring point coordinate data about a three-dimensional object, a database component (105), a processor (103) and a user interface (110). The processor (103) is operable to generate modeled data (105) from the point coordinate data and to segment the modeled data (124) into feature data (122) representing a plurality of features of the object (118). The data is organized so that features of the 3D objects can be automatically extracted for online query and retrieval. The processor (103) is operable to store the modeled data (124) and the feature data (122) in the database component (105) and retrieve modeled data (124) and feature data (122) from the database component (105) using search criteria representing oobject features of interest. The user interface (110) is operative with the processor (103) to allow a user input search criteria to processor (103) and to display data retrieved by the processor as a representation of an object feature.

Three-dimensional digital library system

Influence of stent configuration on cerebral aneurysm fluid dynamics

Over the past 15 years, coil embolization has emerged as an effective treatment option for cerebral aneurysms that is far less invasive than the long-standing convention of surgical clipping. However, aneurysm recurrence after coil embolization is not uncommon: recurrence rates as high as 50% have been reported in the literature. One factor that may contribute to recurrence after coiling is residual flow into the aneurysmal sac. At present, there is limited quantitative knowledge of the relationship between coil packing density and aneurysmal inflow. We present an in vitro fluid dynamic study of basilar tip aneurysm models that elucidates this relationship. At physiologically normal flow rates, we found that a packing density of 28.4% decreased aneurysmal inflow by 31.6% in a wide-neck model, and that a packing density of 36.5% decreased aneurysmal inflow by 49.6% in a narrow-neck model. Results also indicated that coiling reduced aneurysmal inflow more significantly at lower parent vessel flow rates, and that coiling reduced neck-plane velocity magnitudes more significantly for narrow-neck aneurysms. Our study provides novel quantitative information that could ultimately contribute to improved outcomes for patients with cerebral aneurysms by enabling more effective coil embolization.

Quantitative effects of coil packing density on cerebral aneurysm fluid dynamics: an in vitro steady flow study.

Advances in Geometric Modeling and Feature Extraction on Pots, Rocks and Bones for Representation and Query via the Internet

This paper describes development of a storage, archival, and sketch-based query and retrieval system for 3D objects. The process and results provide a model for a Digital Library of 3D data for further study and analysis. The initial focus has been Native American ceramic vessels, scanned and defined as a set of three-dimensional triangulated meshes composed of points and triangles. The process involves modeling the data with parametric surfaces, and extracting relevant features to raise the level of abstraction of data. The project uses a class based XML schema to catalog and organize vessel data. A visual query process was developed to permit users to interact with the data using sketches or by selecting sample vessel shapes to augment text and metric search criteria to retrieve original and modeled data, and interactive 2D and 3D models.

http://www.vintagephoto.com/reference/3d_digLib.pdf

Daniel Collins

Papers

Three-dimensional digital library system

Influence of stent configuration on cerebral aneurysm fluid dynamics

Quantitative effects of coil packing density on cerebral aneurysm fluid dynamics: an in vitro steady flow study.

Advances in Geometric Modeling and Feature Extraction on Pots, Rocks and Bones for Representation and Query via the Internet

A 3D Digital Library System: Capture, Analysis, Query, and Display