EG UK Theory and Practice of Computer Graphics 2005

Permanent URI for this collection

https://diglib.eg.org/handle/10.2312/900

Browse

Now showing 1 - 20 of 27

Augmented Reality Scenarios for Guitar Learning
(The Eurographics Association, 2005) Liarokapis, F.; Louise M. Lever and Mary McDerby
In this paper, an experimental self-teaching system capable of superimposing audio-visual information to support the process of learning to play the guitar is proposed. Different learning scenarios have been carefully designed according to diverse levels of experience and understanding and are presented in a simple way. Learners can select between representative numbers of scenarios and physically interact with the audio-visual information in a natural way. Audio-visual information can be placed anywhere on a physical space and multiple sound sources can be mixed to experiment with compositions and compilations. To assess the effectiveness of the system some initial evaluation is conducted. Finally conclusions and future work of the system are summarized.
Click and Brush: A Novel Way of Finding Correlations and Relationships in Visualizations
(The Eurographics Association, 2005) Wright, Michael A. E.; Roberts, Jonathan C.; Louise M. Lever and Mary McDerby
Brushing is a commonly used interaction technique that allows users to select items or an area of the visualization as the user moves the mouse. Brushing is often used with multiple views, where any co-related information is simultaneously highlighted in these linked views. Brushing is a direct manipulation technique where interaction is performed directly with the visualization. Similar effects can be engendered through indirect manipulation, using dynamic query sliders. In fact, such indirect manipulation can be more effective as the user is able to both highlight and constrain interesting features. In this paper we present a new brushing technique, called Click and Brush , that allows the user to both highlight correlations and constrain intersections in the data using direct manipulation. Users are able to highlight data (brush), fix this subset (click) and explore further intersections (subsets) of this data through further brushing operations.
Fast Simulation of Facial Tissue Deformations Using Mass-Spring Chain Algorithm
(The Eurographics Association, 2005) Duysak, A.; Zhang, J. J.; Louise M. Lever and Mary McDerby
We propose a method to develop a unique head model to be used in craniofacial surgery simulations. This method considers the shape of the head and skull structure and provides a polygonal model, which includes different tissue layers with realistic tissue thickness. We also introduce the use of the new deformation simulation technique called mass-spring chain algorithm in simulation of facial tissue deformations caused by operations on the bone structure. This method produces plausible results and considerably reduces the simulation time.
Real-Time Animation of Particles and Seaweeds in Underwater Scenes
(The Eurographics Association, 2005) Coulais, Y.; Ghazanfarpour, D.; Terraz, O.; Thon, S.; Louise M. Lever and Mary McDerby
Water is one of the most important natural phenomena to be rendered in computer graphics. Although ocean waves animation has been well studied in Computer graphics, only few studies have been done for underwater animation. In this paper, we present a new real-time method for animation of suspended particles and seaweeds in underwater scenes. One of the main advantages of this method, compared to other approaches, is the real-time animation of submerged objects by taking into account some natural underwater forces that govern their movements, such as forces generated by water surface in deep and shallow waters as well as underwater currents. Taking into account forces generated by ocean surface is an original approach in Computer Graphics. In addition, real-time animation of complex underwater scenes composed of a great number of particles and seaweeds can be performed by the use of appropriate levels of details.
Real-time Simulation of Crowds Using Voronoi Diagrams
(The Eurographics Association, 2005) Champagne, J.; Tang, W.; Louise M. Lever and Mary McDerby
In this paper, we present a novel approach for real-time simulation of crowds. Our method is to compute generalised 2D Voronoi diagrams on environment maps for the locations of agents in the crowds. The Voronoi diagrams are generated efficiently with graphics hardware by calculating the closest Voronoi site and the distance to that site using polygon scan conversion and the z-buffer depth comparison. Because Voronoi diagrams have unique features of spatial tessellations which give optimised partitions of space for locating the agents especially groups of agents in a virtual environment, agents in the same group are placed within the Voronoi region which encloses the nearest locations to the geometric centre of the group. Each group of agents within its own Voronoi region follows the geometric centre of the region that is moving on the paths of the maps. During the simulation, agents in groups move closely together and avoid collusions with other groups on the way. With carefully designed rules for collision response the algorithm can generate natural-looking group behaviors of large crowds in real-time. Each agent within a group only detects collisions with other agents of the group and with static obstacles in the environment. Efficiency of the simulation is also gained through such multi-level behavioral simulation approach.
Ubiquitous Virtual Reality: Accessing Shared Virtual Environments through Videoconferencing Technology
(The Eurographics Association, 2005) Pfeiffer, Thies; Weber, Matthias; Jung, Bernhard; Louise M. Lever and Mary McDerby
This paper presents an alternative to existing methods for remotely accessing Virtual Reality (VR) systems. Common solutions are based on specialised software and/or hardware capable of rendering 3D content, which not only restricts accessibility to specific platforms but also increases the barrier for non expert users. Our approach addresses new audiences by making existing Virtual Environments (VEs) ubiquitously accessible. Its appeal is that a large variety of clients, like desktop PCs and handhelds, are ready to connect to VEs out of the box. We achieve this combining established videoconferencing protocol standards with a server based interaction handling. Currently interaction is based on natural speech, typed textual input and visual feedback, but extensions to support natural gestures are possible and planned. This paper presents the conceptual framework enabling videoconferencing with collaborative VEs as well as an example application for a virtual prototyping system.
Perceptually-Oriented Interest Management In Large-Scale Networked Virtual Environments
(The Eurographics Association, 2005) Dunwell, I.; Whelan, J. C.; Louise M. Lever and Mary McDerby
Amongst the most significant challenges in developing large-scale multi-user virtual environments is the efficient filtering of data to each user - a process commonly described as "interest management". This work-in-progress paper presents a broad summary of existing approaches, placing an emphasis upon the relationship between interest management and human perception. Subsequently, an introduction to the challenges in evaluating the success of interest management, given such a relationship to perception, is presented. The initial development of a test environment aimed at overcoming some of the challenges in providing a platform for such evaluation is then described, together with discussion of a perceptually-oriented approach to interest management which relies on the description of perception as a dynamic field, formed by analysis of the user's focus.
Towards Realism in Facial Image Prototyping: Results of a Wavelet MRF Method
(The Eurographics Association, 2005) Tiddeman, Bernard; Stirrat, Michael; Perrett, David; Louise M. Lever and Mary McDerby
The ability to combine multiple images to produce a composite that is representative of the set has applications in psychology research, medical imaging and entertainment. Current techniques using a combination of image warping and blending suffer from a lack of realism due to unrealistic or inappropriate textures in the output images. This paper describes a new method for improving the representation of textures when blending multiple facial images. We select the most likely value for each pixel, given the values of the neighbouring pixels, by learning from the corresponding values in the training set i.e. we use a Markov Random Field (MRF) texture model. We use a multi-scale neighbourhood and separate low and high frequency information using a wavelet transform. This ensures proper correlations of values across spatial scales and allows us to bias the global appearance to the mean for the set, while selecting more specific texture components at higher resolutions. We validate our results using perceptual testing that shows that the new prototypes improve realism over previous techniques.
Integrating Abstract and Physical Molecular Model Interaction
(The Eurographics Association, 2005) Thorne, Dave; Pettifer, Steve; Attwood, Terri; Louise M. Lever and Mary McDerby
Historically, bioinformaticians have carried out protein analysis in one of two ways: by concentrating on either the physical structural representation of the subject data or a more abstract sequential representation. This paper describes a system currently in development at The University of Manchester that attempts to unify these two paradigms. We discuss the use of high-end rendering techniques to greatly increase the level of detail and interactivity of molecular visualisation, and describe the requirements placed upon that visualisation by the relationship between the abstract and physical models.
Freehand 3D Curve Recognition and Oversketching
(The Eurographics Association, 2005) Han, Li; Amicis, Raffaele De; Conti, Giuseppe; Louise M. Lever and Mary McDerby
In the CAD/CAS field, the increasing domination of spline-based graphic objects has driven a great attention to methods focusing on the management of free-form curves. Based on the quick brainstorm illustration and stepwise refinement characteristics in conceptual designing stage, we present a method, which automatically reconstructs the designer s free-form 3D curve through recognizing his design intention . This algorithm automatically extracts the relevant control points through corner detection and dynamic-threshold sampling mechanism; as a result the Bspline curve is approximately produced. Furthermore, considering the ambiguity of designer s intention during the conceptual designing, this redraw operation feature is implemented through the so-called over-sketching . For this we introduce constrained length and tangent angle features, which supports fully free form 3D curve sketching, and it is capable of effectively smoothen transition interval. The method has been tested with various types of sketches, which are rendered in 3D scene environment. We further discuss the modification and its application to surfaces.
Arachnid Simulation: Scaling Arbitrary Surfaces
(The Eurographics Association, 2005) Cenydd, L. ap; Teahan, W.; Louise M. Lever and Mary McDerby
There has been little research done into the realistic simulation of creatures with the ability to crawl across arbitrary surfaces, clamber up walls and walk across ceilings. Realistic simulation of such feats would be of benefit to fields such as arthropod phobia therapy, the animation of computer game characters and Artificial Life research. We have implemented a system that can produce real-time simulation of a spider traversing across an arbitrary surface. The simulation uses a combination of a behavioral system, an orientation system, a procedural gait generator and an inverse kinematics solver to produce the real-time dynamic animation.
Virtual Sculpting Using Implicit Surfaces with Scattered Data Interpolation
(The Eurographics Association, 2005) Zhang, K.; Noble, R. A.; McDermott, R. J.; Wilson, A.; Louise M. Lever and Mary McDerby
This paper presents a virtual sculpting system that shows an approach to the interactive deformation of soft objects. The soft objects are represented by implicit surfaces which are visualized using a constrained particle method. Those particles are arranged in an efficient cubical structure in which its processing speed is faster than some other surface sampling algorithms. The sculpted result can be stored in a compact form by interpolating the constrained particles using scattered data interpolation. The user can control the complexity of the sculpted shape by specifying the sampling density. In addition, the way in which the tool deforms the clay can be controlled explicitly by some control parameters. The surfaces are displayed with a stereoscopic viewer and the virtual tools are manipulated using a spaceball with 6 degrees of freedom.
Simulation and Visualization of a large scale Real Time Multi-Robot system
(The Eurographics Association, 2005) Al-Hudhud, G.; Ayesh, A.; Istance, H.; Louise M. Lever and Mary McDerby
This paper describes the software implementation and the visualization aspects of an interaction-communication protocol within a large scalable multi-robot system. It investigates the current communication protocols within multi-agent systems and the feasibility to transfer them into a virtual environment system that performs a speci- fied task intelligently, embedding human capability into the control system software. The proposed system allows dynamic changes, i.e. the user may be able to continuously issue commands, or modify tasks. The work presented exploits the Virtual Environment Centre VEC. The semi-immersive full scale environment within the VEC allows the user to better understand the robots behaviour and in turn test whether they simulate the expected behaviour. The use of a semi-immersive full-scale environment also gives an increased level of presence enabling the user to believe they are within their own simulation. It also presents a prototype for a robot automatic fire extinguishing system as a test application area.
skML a Markup Language for Distributed Collaborative Visualization
(The Eurographics Association, 2005) Duce, D. A.; Sagar, M.; Louise M. Lever and Mary McDerby
This paper describes a reference model and a markup language for representing processing and dataflow in distributed collaborative visualization applications. The language, skML, enables processing to be represented at each of the three layers: conceptual, logical and physical defined in the reference model. skML is an XML application. A particular feature of the approach is the use of RDF to associate annotations with skML elements, for example to describe resource constraints. An interactive editor for skML and prototype tools to use skML with IRIS Explorer and OpenDX are described. Extension to other visualization systems such as AVS and VTK is discussed. The paper concludes by comparing skML to other languages and environments for scientific workflow.
Visualization of Smoothed Particle Hydrodynamics for Astrophysics
(The Eurographics Association, 2005) Walker, Rick; Kenny, Peter; Miao, Jingqi; Louise M. Lever and Mary McDerby
Scientific visualization still presents a number of challenges. Effective visualization straddles several problem domains - the data structures needed to support visualization of large data sets, rendering techniques for fast and interactive display of this data, and enough understanding of the data involved to construct visualizations that provide real insight into the problem. Data from Smoothed Particle Hydrodynamics simulations is of particular interest, due to its time-dependent, point-based nature and its prevalence in simulation in astrophysics in areas such as star formation and evolution. This paper looks at some of the issues associated with building a useful, usable visualization tool for SPH data from astrophysics, and describes a prototype of such a system. This paper describes work in progress.
Simulating the Cumulative Effects of Multiple Impacts using 'Fracture Maps'
(The Eurographics Association, 2005) Clifton, T.; Louise M. Lever and Mary McDerby
Abstract Much research has been carried out within the computer graphics community to simulate the effects of collisions between deformable and rigid bodies, but little has been proposed to take into account the effects of one collision, on later impacts. We present a novel approach to model and retain information regarding specific impacts that can be used to better approximate the results of future collisions, taking into account non-visible effects caused as objects collide within a scene. We propose the notion of fracture maps to store and evaluate stress and strain factors for polygonal meshes in order to accommodate the cumulative effects of impacts, even if these effects are not immediately visible to the human eye. We describe the initial work carried out towards this research, including the methodology to create and update these impacts and how they can be used to determine both deformation and decimation of meshes from multiple impacts. We discuss requirements for completing the research, and future directions we would extend the concept further.
Selective Parallel Rendering for High-Fidelity Graphics
(The Eurographics Association, 2005) Debattista, K.; Sundstedt, V.; Pereira, F.; Chalmers, A.; Louise M. Lever and Mary McDerby
High-Fidelity rendering of complex scenes is one of the primary goals of computer graphics. Unfortunately, high- fidelity rendering is notoriously computationally expensive. In this paper we present a framework for high-fidelity rendering in reasonable time through our Rendering on Demand system. We bring together two of the main acceleration methods for rendering: selective rendering and parallel rendering. We present a selective rendering system which incorporates selective guidance. Amongst other things, the selective guidance system takes advantage of limitations in the human visual system to concentrate rendering efforts on the most perceptually important features in an image. Parallel rendering helps reduce the costs further by distributing the workload amongst a number of computational nodes. We present an implementation of our framework as an extension of the lighting simulation system Radiance, adding a selective guidance system that can exploit visual perception. Furthermore, we parallelise Radiance and its primary acceleration data structure, the irradiance cache, and also use the selective guidance to improve load balancing of the distributed workload. Our results demonstrate the effectiveness of the implementation and thus the potential of the rendering framework.
Implementing an Improved Stereoscopic Camera Model
(The Eurographics Association, 2005) Froner, Barbara; Holliman, Nick; Louise M. Lever and Mary McDerby
The usable perceived depth range of all stereoscopic 3D displays is limited by human factors considerations to a bounded range around the plane of the display. To account for this our Three Region stereoscopic camera model is able to control the depth mapping from scene to display while allowing a defined region of interest in scene depth to have an improved perceived depth representation compared to other regions of the scene. This can be categorized as a focus+context algorithm that manipulates stereoscopic depth representation along the viewing axis of the camera. We present a new implementation of the Three Region stereoscopic camera model as a Utility plug-in for the popular modelling and rendering package 3ds max. We describe our user interface, designed to incorporate stereoscopic image generation into the user s natural work flow. The implementation required us to overcome a number of technical challenges including; accurately measuring scene depth range, simulating asymmetric camera frustum in a system only supporting symmetric frustum, merging multiple renderings and managing anti-aliasing in layered images. We conclude from our implementation that it is possible to incorporate high quality stereoscopic camera models into standard graphics packages.
Keyframing Particles of Physically Based Systems
(The Eurographics Association, 2005) Dingle, Brent M.; Keyser, John; Louise M. Lever and Mary McDerby
This paper will present a way to use keyframing methods for particle motion to enhance the visual effects and user controllability of physically based particle systems. This will be done using an adaptive correction methodology. This will allow for three general types of keyframing: position to position, density to density, and boundary to boundary. While similar techniques have been explored in flocking behaviors and robotic motion planning, this paper implements them in conjunction with physically based systems and allows a comparison of particle based keyframing to keyframing achieved using other methodologies. To illustrate the technique we will present two examples. The first morphs between two particle images. The second forces a smoke-like substance to change into various letters of the alphabet. While these are specific examples the techniques presented herein should apply to most any particle based system to achieve a diverse range of effects.
The Data Surface Interaction Paradigm
(The Eurographics Association, 2005) Lindell, Rikard; Larsson, Thomas; Louise M. Lever and Mary McDerby
This paper presents, in contrasts to the desktop metaphor, a content centric data surface interaction paradigm for graphical user interfaces applied to music creativity improvisation. Issues taken into account were navigation and retrieval of information, collaboration, and creative open-ended tasks. In this system there are no windows, icons, menus, files or applications. Content is presented on an infinitely large two-dimensional surface navigated by incremental search, zoom, and pan. Commands are typed aided by contextual help, visual feedback, and text completion. Components provide services related to different content modalities. Synchronisation of data surface content sustains mutual awareness of actions and mutual modifiability. The prototype music tool was evaluated with 10 users; it supported services expected by users, their creativity in action, and awareness in collaboration. User responses to the prototype tool were: It feels free, it feels good for creativity, and it s easy and fun to use.

Browse

Browsing EG UK Theory and Practice of Computer Graphics 2005 by Issue Date

Results Per Page

Sort Options