Eddy Flerackers

Hasselt University · Expertise Centre for Digital Media (EDM)

In this paper we set out to nd a digital painting technique which allows the recreation of scenes from childrens books or graphic novels for usage in mobile games. The idea is to give the impression that scenes are being hand-painted at the moment the player is moving through them. To this end, we propose a technique for digital painting, mesh-base...

In this paper we set out to find a digital painting technique which allows the recreation of scenes from children’s books or graphic novels for usage in mobile games. The idea is to give the impression that scenes are being hand-painted at the moment the player is moving through them. To this end, we propose a technique for digital painting, mesh-b...

From the Back Cover: The data deluge problem is increasing. Every day the results of scientific experiments, monitoring instruments, medical analysis, and social networks add petabytes to the world’s information. Many future experiments will generate data that will be substantially more than has been collected throughout history. How can we effecti...

Advanced digital paint systems, based on accurate simulation models for the paint, brush and canvas interaction enable a virtual painting environment familiar to artists, but also allow for new ways of expressivity. The new FluidPaint co-located real-brush-input & canvas-display systems put extremely high demands on the real-time image processing a...

To reduce the learning curve and enhance expressiveness, Human Computer Interfaces continuously improve to mimic object interaction in the real environment. A novel digital painting system has been developed that provides the artist with the expressiveness of virtual painting by using real and wet brushes. The kernel of the system is an interactive...

Gedurende de laatste jaren steeg de populariteit van mobiele computers om de bezoekerservaring te verrijken en vonden deze apparaten hun weg naar musea en andere erfgoedinstellingen. De voordelen van het gebruik van mobiele computers zijn duidelijk: informatie kan op een dynamische manier via het toestel gepresenteerd worden, zonder dat de fysieke...

Designers and developers of virtual environments have to consider that providing adaptation in virtual environments is important to comply with users’ different characteristics. Due to the many possibilities of adaptation that a designer can think of, it is necessary to support the integration of adaptation in the application in a rapid and practic...

We present Archie: a mobile guide system that uses a social-constructivist approach to enhance the learning experience for museum visitors [1, 2]. One of the implementations we created is a collaborative game for youngsters that is build on top of a generic mobile guide framework. The framework offers a set of services that support the creation of...

This paper presents FluidPaint, a novel digital paint system using real wet brushes. A new interactive canvas, accurately registering brush footprints and paint strokes in high precision has been developed. It is based on the real-time imaging of brushes and other painting instruments as well as the real-time co-located rendering of the painting re...

In the past decades, the use of mobile guides as tools to enrich the visitors' experience has found its way into many museums and cultural tourist sites. The applicability, effect and behavior of these kinds of technologies, however, remain hard to assess. Moreover, every museum or cultural tourist site has its own specific context according to whi...

Purpose – Scalability is an important research topic in the context of networked virtual environments (NVEs). This paper aims to describe the ALVIC (Architecture for Large-scale Virtual Interactive Communities) approach to NVE scalability. Design/methodology/approach – The setup and results from two case studies are shown: a 3-D learning environme...

In the visual programming community, many interesting graphical metaphors have been reported upon for representing computer programs graphically. Most of them have a 2D or 2.5D appearance on the screen in order to reflect the inherent multi-dimensionality of the programming constructs being represented. By going into a three-dimensional representat...

Rendering high-quality shadows in real-time is a challenging problem. Shadow mapping has proved to be an efficient solution, as it scales well for complex scenes. However, it suffers from aliasing problems. Filtering the shadow map alleviates aliasing, but unfortunately, native hardware-accelerated filtering cannot be applied, as the shadow test ha...

In this paper we report on our work to develop a novel input technique for a digital paint system. Using a brush with infrared (IR) light emitting fibers, we were able to create a natural paint interface on an interactive table. This IR-brush adds two important properties to our paint environment: haptic feedback and an accurate brush footprint. Th...

The use of handheld computers as a tool to enrich the museum experience has found its way into many museums, opening up new possibilities to increase the attractiveness of museum visits, especially for youngsters. We developed a mobile guide framework that supports the creation of mobile guides and adheres to social-constructivist principles of lea...

Given the ever increasing processing power within today's personal computers, one can ascertain a still increasing tendency towards PC- based visualization systems for industrial and architectural design. Along with this trend, a migration from static visualization towards animated visualization and simulation is also taking place, as well as a mi...

Microcomputers are increasingly becoming capable of supporting high-end multimedia applications. The multimedia extensions in current central processing units, together with the supplementary functionality of audio, graphics and networking plug-in boards, make it possible to realize applications that a very few years ago still needed supercomputer...

The subject of the paper is the computer-based rendering of bi-tonal images of 3D scenes looking alike pen-and-ink drawings generated manually. Traditional pen-drawings consist of thousands of pen-strokes,implying their generation can be a time consuming process. Especially when animated sequences of this kind of drawings are to be generated, manua...

This paper presents a technique to drastically reduce the size of a population, while still maintaining sufficient diversity for evolution. An advantage of a reduced population size is the reduced number of fitness evaluations necessary. In domains where calculation of fitness values is expensive, this results in a huge speedup of the search. Addit...

In this paper, several techniques will be presented to constrain the growth of solutions that are constructed by genetic programming. The most successful technique imposes a maximum size on the created individuals of the population that depends solely on the size of the best individual of the population. This method will be compared with other meth...

In this paper, we present a method to implement a navigation system for an intelligent agent that exists in a virtual world to generate collision-free motion. To observe the world, the agent uses virtual sensors consisting of the depth buffer information of a rendered image of the scene. This information is used to generate low-level collision avoi...

In most existing immersive virtual environments, 3D geometry is imported from external packages. Within ICOME (an Immersive Collaborative 3D Object Modelling Environment) we focus on the immersive construction of 3D geometrical objects within the environment itself. Moreover, the framework allows multiple people to simultaneously undertake 3D model...

Conventional educational material is ever more complemented with computer based multimedia material. In order to make this material available to teachers and students in a structured manner, we developed a multimedia database and accompanying tools for creating, manipulating and formatting the teaching content (K. Coninx et al., 1997). Recently, we...

Menus and dialog boxes are useful enhancements for the direct manipulation based interaction style of Virtual Environments. In this paper an implementation of 2D HCI techniques in immersive Virtual Environments is discussed. The applicability of 2D techniques for interaction with the environment is illustrated in the case of a BOOM for immersive vi...

The European project ELECTRA is concerned with the introduction of multimedia / telematics support to enhance the accessibility (local, regional and international) of learning material and to promote collaborative work. For the purpose of this paper we concentrate on two workpackages in the Limburg University Centre. The Interactive Multimedia Serv...

Visinet is a trans-European 3D collaborative design project that brings together computer scientists, application developers, design specialists, and users in the context of shared environments supported by ATM networks. Experiments and trials have been conducted for the key application domains of architectural and industrial design. Different type...

Virtual environments and other applications of computer-generated scenes are emerging. This increases the demand for tools for efficient creation of the virtual worlds and interaction with the components in the virtual world. Introduction of immersiveness in the modeling process seems promising, but a number of issues related to immersive modeling...

An automatic system is proposed that can locate line breaks. After a description of line-transmission systems and the linebreak problem, a solution is studied that uses intermediate loopbacks along a line equipped with solid-state switches. The features of solid-state switches allow a simple implementation and are especially interesting in the case...

This paper presents new techniques for speeding up the ray tracing algorithm. By projecting the scene to be ray traced onto perpendicular planes, subdividing the planes with a 2D subdivision scheme (regular grid- and quadtree structures) and traversing these projected scenes throughout the subdividing structures, the methods reported upon exploit t...

In the visual programming community, many interesting graphical metaphors have been reported upon for representing computer programs graphically. Most of them have a 2D or 2.5D appearance on the screen in order to reflect the inherent multi-dimensionality of the programming constructs being represented. By going into a three-dimensional representat...

This chapter reviews a modular system for manipulating image sequences. An overview of the xXX system architecture (software as well as hardware architecture) is define and explains how the user-extensibility is realized. Software extensibility is offered to the users in the form of specific image manipulation effects, specialized editors, and addi...

This paper is about ExTwAnPaSy, an Extensible Two-dimensional Animation/Paint System. ExTwAnPaSy is designed as a testbed for integrating various animation and painting techniques. Utilizing a uniform internal representation (and accompanying operations on it) for all geometric primitives, ExTwAnPaSy can integrate direct manipulation-, key-framing...

In the visual programming community, many interesting graphical representations have been reported. Most have a 2D or 2.5D appearance on screen to reflect the inherent multi-dimensionality of the programming constructs being represented. By going to a three-dimensional representation, this reflection can go a step further. With ever increasing 3D g...

Global illumination models have recently received a considerable amount of attention in realistic image synthesis research. Especially radiosity methods for realizing the illumination in scenes exhibiting global Lambertian diffuse reflection have been reported upon. Since the introduction of the progressive refinement methodology, the performance o...

Since its appearance in computer graphics research, ray tracing has attracted considerable attention, especially with regard to speeding up the algorithm. This paper presents an acceleration scheme based on utilizing parallel processing techniques. It is shown how an existing ray tracing acceleration technique – Amanatides’ voxel transversal algori...

Many ray tracing systems lack the availability of curved surfaces, since the calculation of the intersection between a ray and such a surface is a computation-intensive algorithm. Several speedup techniques have been presented already. But most of these methods don’t use coherence between neighbouring rays. In order to exploit this coherence in ray...

When designing and developing a 3D computer animation system, numerous interrelated issues and concepts have to be taken into account. Given our limiting factors of a low starting budget and the knowledge that current and future animation systems require huge amounts of processing power, we came to the development of a 3D computer animation system...

The application of visual programming techniques in a computer animation environment is described. By combining the possibilities of an interactive animator-oriented user interface, a unified and integrated curve paradigm, and visual language constructs, a system in which the utilization of graphics brings programming capabilities to nonprogramming...

In Computer Graphics, aliasing occurs by the reconstruction of a continuous image starting from a set of discrete samples. Most anti-aliasing algorithms give best results in conjunction with a scan-line algorithm. Algorithms for anti–aliasing objects using a Z-buffer were believed to be difficult. Here we present a new anti-aliasing method for filt...

Within the visual programming paradigm there is a vast range of potential for creating program representations. To benefit by these possibilities, it could be worthwhile to make the program representation open-ended, i.e. modifiable to the specific needs of the user. The authors elucidate the tentative result of their research in this field around...