In this paper, we explore image reconstruction from irregularly spaced samples using natural neighbour interpolation. We sample the image irregularly using techniques based on the Laplacian or the derivative in the direction of the gradient. Local coordinates based on the Vorono...

Hierarchical subdivision techniques remove the need for a-priori meshing of surfaces when approximating global illumination. In addition they allow progressive re nement of the solution. However, when subdivision is based upon Monte Carlo methods, due to the stochastic nature of such&...

One of the biggest areas of scientific visualization (ViSC) application is Medicine: with the evolution of image acquisition techniques the capacity and fidelity of image diagnosis were extended. Due to the large number of medical exams that output images, several visualization s...

This articel presents a new approach to interaction with 3D objects of virtual models in the context of digital libraries, which was developed as part of the author`s ongoing PhD research. Collaborative net- worked environments support users in their work with shared content...

Most 3D modelling tools available today operate using interfaces based on traditional static menus, which implies that the user must go through a long training period before he can use the modelling tool in a productive manner. In this paper we explore the definition&#x...

This paper presents a simple, robust and practical, yet fast algorithm for triangulation of points on the domain of trimmed Bézier surfaces. These R2 points are input to this algorithm by a surface sampler. A set of polygons is formed from these samples, which are&...

This paper focuses on a new radiosity approach. Using a new geometrical model that describes any surface with an atlas of \disk-like patches", i.e. a set of pieces covering the surface that can overlap each other, we express the radiosity function in a new...

In this paper we describe new metrics for the evaluation of collision detection techniques. Through careful study of common applications of these techniques we have developed a series of comparative tests that should be conducted when evaluating a collision detection algorithm. W...

An octree is a well known hierarchical spatial structure which is widely used in Computer Graphics algorithms. One of the most frequent operations is the computation of the octree voxels intersected by a straight line. This has a number of applications, such as ray-obje...

Polynomial representations, such as Bezier curves, B-splines or NURBS, form the basis of numerous surface modelling packages. Although they possess properties that result in fast, efficient software, they have some limitations in terms of the shapes that can be modelled and the&#...

This paper presents a new, accurate, efficient and unified method for dynamic animation of one, two or three-dimensional deformable objects. The objects are modelled as d-dimensional juxtapositions of ddimensional patches defined as parametric blending of a common d-dimensional mesh of...

Non-uniform basis functions for construction of interpolating and approximating spline curves and surfaces are presented. The construction is based on the theory of B-splines and enables a continuous change from interpolation to approximation of given data. It is also possible to ...

The alternating sum of volumes (ASV) decomposition is a widely used technique for converting a b-rep into a CSG model, with all its implicit uses and advantages -like form feature recognition, among others. The obtained CSG tree has convex primitives at its leaf nodes,&...

Computer assisted image fusion provides an easy and accurate way to interpret and compare medical image pairs. Subjective expectations of human interpretator become less important when pixel-by-pixel-variations are calculated by computer. The estimation of sizes and locations of the ...

Presented paper describes the method for finding the intersection of class space rational Bezier curves. The problem curve/curve intersection belongs among basic geometric problems and the aim of this article is to describe the new technique to solve the problem using relief perspe...

In this paper, we will present an increased-security concept for systems administering patient-data and DICOM (digital imaging and communication in medicine) images. The system presented here is an intranet/internetbased PACS and has been developed at the institute of telematics (IT)&...

The digital television development is one of the most important events in the history of television broadcasting. This paper highlights the user interface issue in digital television environment. We will not discuss the usability of user interface design, but rather the implement...

This paper describes a method for generating flower growth animation in which a petal surface and shape can be changed in real time. Most plant modelling currently animates the plant development process by assuming a time interval and the corresponding growth direction, and cannot&...

A new algorithm for image-space CSG rendering is presented, based on subtraction of convex objects in a specific sequence. The algorithm has been implemented on OpenGL PC graphics hardware, as well as SGI workstations. Advantages of the algorithm include simpler implementation, closer a...

This paper presents the RECTANGULAR FISHEYE VIEW, an interactive focus–and–context presentation technique for large raster images on mobile computers with small displays and limited processing power. Both the viewing of locally available images and the demand–driven display and transmission...