1777796
A System for the Non-Linear Modelling of Deformable Procedural Shapes
This paper describes a fully interactive modelling system, which we have called ClayWorks, for defining the implicit geometry of 3D objects using parametric base primitives and deformations. The goal of this system is to provide a means for describing object data and its creation history by using a series of parametric steps that can be modified post-creation in a non-linearmanner. The advantages of this approach are that unlike other modelling approaches, it enables compact object descriptions, an intuitive modelling process, a simple approach to multiresolution objects, real-time feedback during the modelling process and a render independent object representation.
18996618
The Production of Volume Data from Triangular Meshes Using Voxelisation
Voxelisation is the term given to the process of converting data from one source type into a three dimensional volume of data values. The techniques known collectively as volume visualisation can then be applied to the data in order to produce a graphical representation of the object. This paper gives a practical approach to the voxelisation of data in the form of triangular meshes, and demonstrates the use of the method on various datasets. Visualisation is achieved by a method also described in the paper.
2186746
3D distance fields: a survey of techniques and applications
A distance field is a representation where, at each point within the field, we know the distance from that point to the closest point on any object within the domain. In addition to distance, other properties may be derived from the distance field, such as the direction to the surface, and when the distance field is signed, we may also determine if the point is internal or external to objects within the domain. The distance field has been found to be a useful construction within the areas of computer vision, physics, and computer graphics. This paper serves as an exposition of methods for the production of distance fields, and a review of alternative representations and applications of distance fields. In the course of this paper, we present various methods from all three of the above areas, and we answer pertinent questions such as How accurate are these methods compared to each other? How simple are they to implement?, and What is the complexity and runtime of such methods?.
10888216
Hypertexturing complex volume objects
This paper will examine hypertexture rendering techniques and will demonstrate how volume data sets may be adapted in order for hypertexture to be applied. Details are given of a process for the conversion of complex objects, such as CT scans, into accurate distance fields. Hypertexture is applied to these objects and example renderings include the UNC CThead, a chess piece, a dodecahedron and a tank. Additional information is given about soft objects, density modulation functions, ray marching and controlling hypertexture application.
18480565
Volumes of expression: artistic modelling and rendering of volume datasets
This paper presents the design and implementation of artistic effects in modelling and rendering of volume datasets. Following different stages of a volume-based graphics pipeline, we examine various properties of volume data, and illustrate how expressive and non-photorealistic effects can be implemented. We demonstrate that the true 3D nature of volume data makes it particularly applicable for this use, allowing the addition of complex effects at the modelling stage as well as during rendering.
6934253
Shape representation using space filled sub-voxel distance fields
Voxelisation is the process of converting a source object of any data type into a three-dimensional grid of voxel values. This voxel grid should represent the original object as closely as possible, although some inaccuracies will occur due to the discrete nature of the voxel grid representation. In this paper we report our ongoing research into methods for representing objects as voxelised distance fields, in particular we report fast methods for accurate distance field production. A review of current alternative voxelisation methods is also given.
1818077
I-Vote: an audience voting system
In this paper, we describe the I-Vote system for audience response voting at the Olympic Games. The audience members vote by using a $2 handheld device that they can keep as a souvenir. The devices are simple to use, come in multiple designs, and are tradable. These devices do not hold any personal information so privacy is never an issue. The vote results are presented on a large public display, which is loaded with information in the form of graphs that are quickly understood. People can retrieve their personal votes later on the Internet. The system was designed through a process involving brainstorming, creating scenarios, searching for information, doing cognitive walkthroughs, developing prototypes, and revising and refining ideas.
43107545
A Theory of Qualified Types
Abstract This paper describes a general theory of overloading based on a system of qualified types. The central idea is the use of predicates in the type of a term, restricting the scope of universal quantification. A corresponding semantic notion of evidence is introduced and provides a uniform framework for implementing applications of this system, including Haskell style type classes, extensible records and subtyping. Working with qualified types in a simple, implicitly typed, functional language, we extend the Damas-Milner approach to type inference. As a result, we show that the set of all possible typings for a given term can be characterized by a principal type scheme, calculated by a type inference algorithm.
42586645
The music is the message
the music being played by her tiny mobile audio appliance. She's standing waiting for a train. Other commuters swarm nearby, headphones on, listening in more muted ways to the soundtracks they've chosen to accompany today's episode of their daily routine. Mobile music players—iPods, Walkmans and the like—are exciting for those of us involved in thinking about the future of mobile devices and services. Like the mobile phone—increasing numbers of which also sport a music player—these are gadgets that people actually desire, and aspire to own. They have vast storage capacities, increasingly sophisticated processors and pleasing, effective mechanisms for users to control their func-tionality. From click and jog wheels to high-resolution color displays, these players are far from being the impoverished devices that typified mobile platforms just a few years ago. And there are hundreds of millions of them in circulation—Apple sold five million in the first quarter of 2006 alone. But at the same time, these marvelous mobiles could be seen as an obstacle to the bright futures dreamt up in the research labs. How will people be able to make use of the ubiquitous computing infrastructure being envisaged, the anytime, everywhere access to information and services, when they are immersed in digital sound bubbles of their own choosing? Some mobile listeners, at first sight, certainly appear cut off. Another scene: A young man stares out of a train window, watching the long green fields flash by. His eyes are bright but still; his gaze betrays a mood of deep reflection. Listening to music on expensive , noise-reducing headphones, what is he thinking? Is he sadly contemplating a lover left or anticipating a longed-for meeting at his destination? How can we design mobile services that will fit this context? The conventional clumsy beeps, vibrations, and attention-seeking displays seem out of place. What opportunities are there to build more emphatic systems , systems to enhance the music and environmental experience or to provide ways for the listener to later reflect on the situations they've lived through in relation to the music they've heard? At other times, though, these sound bubbles seem more permeable, don't they? One of the photos of people listening to music available on a popular image-sharing site is entitled " Listening to Kim's iPod and talking to Joe! " A teenager holds a mobile phone to her left ear while wearing the distinctive white music-player headphones. Chatting and …
15786317
Bringing the C Libraries With Us into a Multi-Threaded Future
Textile materials such as fiber and cloth can be dyed more satisfactorily with sulfur dyes or sulfurized vat dyes by allowing an organic mercapto compound and/or an organic sulfur compound capable of generating mercapto groups under dyeing conditions to be present in dye baths. Still more improved dyeing results may be obtained by allowing a sulfite salt compound to be further present in such dye baths.
22559047
Usability of digital libraries