Ioana M. Martin

High-quality texture reconstruction from multiple scans

The creation of three-dimensional digital content by scanning real objects has become common practice in graphics applications for which visual quality is paramount, such as animation, e-commerce, and virtual museums. While a lot of attention has been devoted recently to the problem of accurately capturing the geometry of scanned objects, the acquisition of high-quality textures is equally important, but not as widely studied. In this paper, we focus on methods to construct accurate digital models of scanned objects by integrating high-quality texture and normal maps with geometric data. These methods are designed for use with inexpensive, electronic camera-based systems in which low-resolution range images and high-resolution intensity images are acquired. The resulting models are well-suited for interactive rendering on the latest-generation graphics hardware with support for bump mapping. Our contributions include new techniques for processing range, reflectance, and surface normal data, for image-based registration of scans, and for reconstructing high-quality textures for the output digital object.

Cut-and-paste editing of multiresolution surfaces

Cutting and pasting to combine different elements into a common structure are widely used operations that have been successfully adapted to many media types. Surface design could also benefit from the availability of a general, robust, and efficient cut-and-paste tool, especially during the initial stages of design when a large space of alternatives needs to be explored. Techniques to support cut-and-paste operations for surfaces have been proposed in the past, but have been of limited usefulness due to constraints on the type of shapes supported and the lack of real-time interaction. In this paper, we describe a set of algorithms based on multiresolution subdivision surfaces that perform at interactive rates and enable intuitive cut-and-paste operations.

Sharp features on multiresolution subdivision surfaces

In this paper we describe a method for creating sharp features and trim regions on multiresolution subdivision surfaces along a set of user-defined curves. Operations such as engraving, embossing, and trimming are important in many surface modeling applications. Their implementation, however, is non-trivial due to computational, topological, and smoothness constraints that the underlying surface has to satisfy. The novelty of our work lies in the ability to create sharp features anywhere on a surface and in the fact that the resulting representation remains within the multiresolution subdivision framework. Preserving the original representation has the advantage that other operations applicable to multiresolution subdivision surfaces can subsequently be applied to the edited model. We also introduce an extended set of subdivision rules for Catmull-Clark surfaces that allows the creation of creases along diagonals of control mesh faces.

An adaptive framework for 3D graphics over networks

Abstract Access to and transmission of 3D models over networks becomes increasingly popular. However, the performance and quality of access to remote 3D models strongly depends on system load conditions and the capabilities of the various system components, such as clients, servers, and interconnect. The network graphics framework (NGF) integrates various transmission methods for downloading 3D models in a client–server environment. The NGF automatically selects the optimal transmission method for a given pair of client and server, taking into account characteristics of the model to be transmitted, critical environment conditions, user preferences and the capabilities of the client and the server. The NGF aims to provide constant quality of service across different clients and under varying environment conditions.

Hybrid transcoding for adaptive transmission of 3D content

For traditional multimedia types, transcoding has proven successful in serving variations of the same object at different sizes and using different modalities. Transcoding, which is defined as a transformation that is used to convert multimedia content from one form to another [1], can be naturally extended to 3D data. By their very nature, 3D models are amenable to access through various representation modalities that typically imply trade-offs between complexity, interaction, and download times. In this paper we describe the design and development of an adaptive environment for rendering of 3D models over networks. This environment monitors the resources available and selects the appropriate transmission and representation modalities to match these resources.For traditional multimedia types, transcoding has proven successful in serving variations of the same object at different sizes and using different modalities. Transcoding, which is defined as a transformation that is used to convert multimedia content from one form to another, can be naturally extended to 3D data. By their very nature, 3D models are amenable to access through various representation modalities that typically imply trade-offs between complexity, interaction, and download times. In this paper we describe the design and development of an adaptive environment for rendering of 3D models over networks. This environment monitors the resources available and selects the appropriate transmission and representation modalities to match these resources.

Concurrent computation and data visualization for spherical virus structure determination

The authors present concurrent algorithms and programs for structure determination using structural information obtained through X-ray crystallography and electron microscopy. They introduce two interactive software systems, Emma and Tonitza, that support processing large data sets produced in structural biology experiments.

ARTE—an adpative rendering and transmission environment for 3D graphics

Thus far, a significant body of work has been devoted to the challenges of universal access related to the delivery of traditional multimedia content such as text, images, audio, and video. Less attention has been focused on three-dimensional (3D) digital content, as true market opportunities for 3D graphics over networks have just begun to emerge. In this paper, we present ARTE, an Adaptive Rendering and Transmission Environment that facilitates the delivery 3D models in heterogeneous environments by monitoring the resources available and by selecting appropriate transmission modalities.

Data visualization: Concurrent computation and data visualization for spherical-virus structure determination

The authors present concurrent algorithms and programs for structure determination using structural information obtained through X-ray crystallography and electron microscopy. They introduce two interactive software systems, Emma and Tonitza, that support processing large data sets produced in structural biology experiments.