In this paper we demonstrate the benefits of the most current nVidia graphics chip set for realistic simulation and rendering of dynamic water surfaces in real-time. In particular we employ programmable vertex shaders for the simulation of the water surface height field and for the displacement, transformation and lighting of vertices. To keep bandwidth requirements low a superposition of NURBS surfaces generated by the hardware through OpenGL evaluators and gradient noise implemented in the shader program itself is proposed. Furthermore, environment cube-mapping is used to enable realistic rendering. Our method can efficiently simulate effects such as refraction, reflection and the Fresnel term to model the optical characteristics of water. Although in this work only the simulation of a certain class of natural phenomena is exemplified, the proposed method is suitable for visually representing other effects as well.

Procedural methods are a promising but underused alternative to manual content creation. Commonly heard drawbacks are the randomness of and the lack of control over the output and the absence of integrated solutions, although more recent publications increasingly address these issues. This paper surveys procedural methods applied to terrain modelling, evaluating realism of their output, performance and control users can exert over the procedure. 1

Information visualization is essential in making sense out of large data sets. Often, high-dimensional data are visualized as a collection of points in 2-dimensional space through dimensionality reduction techniques. However, these traditional methods often do not capture well the underlying structural information, clustering, and neighborhoods. In this paper, we describe GMap, a practical tool for visualizing relational data with geographic-like maps. We illustrate the effectiveness of this approach with examples from several domains. All the maps referenced in this paper can be found in www.research.att.com/˜yifanhu/GMap.

Current graphics hardware is now capable of rendering vast numbers of triangles, but geometric throughput to the hardware remains a bottleneck. Two techniques for overcoming that bottleneck are to submit the data in a specific format and once submitted, to leave the data unchanged for as long as possible. Real-time level-of-detail (LOD) algorithms for terrain involve processing massive amounts of geometry. However, most published algorithms are not able to supply this geometry to the graphics card in an optimal format, and must re-submit the geometry each frame. We present an efficient LOD algorithm for terrain rendering that is capable of supplying the graphics card with geometric data in an optimal format and leaving it unchanged over the course of many frames. As well, texture synthesis is performed for the terrain, creating unique textures to cover the rendered surface. ii Acknowledgements Thanks to my advisor Alejo Hausner and my second reader Karan Singh for feedback and

As interactive graphics applications such as driving- and flight-simulators and especially video games, advance towards ever more complex synthetic environments, numerous challenges arise in the modeling, storing, loading, simulating, animating and rendering of the large quantity of data involved. These challenges impose strict limitations upon the designers of typical interactive graphics applications, who, to maintain interactive display rates, must simplify the data that the computer processes in each frame. The goal of this dissertation is to enable the authoring and real-time emulation of highly interactive, large-scale synthetic environments. In order to support very large worlds, we want to present the user with an approximation of both the geometry and behaviors of these worlds, computing only enough detail to emulate a plausible experience based on the limits of the user’s time-varying perception, knowledge, and expectation of the environment. Our approaches for achieving this goal are on-the-fly semantic procedural modeling of a multi-resolution description for geometry and behaviors, an event-driven runtime for managing and displaying these at interactive rates, and a cache mechanism which organizes the geometry for efficient rendering on current graphics hardware. Both as a modeling aid and as a means of data compression, we describe the world procedurally using stochastic subdivision techniques, generating geometric and behavioral detail only as needed by the application. Authored content, in a quadtree structure akin to a scene graph, provides the parameters that guide the procedural generation of the world. We present two new inter-related data structures, the quadtree cache and the quadtree dual, which manage the nested levels of detail of the procedurally generated terrain and object data. The novel interleaved update mechanism of the cache allows us to batch geometry into time-coherent pieces that are well-suited for real-time rendering.

This paper presents a case study in the generation of a planetary terrain model. Several novel techniques were developed as part of the work. A new view-dependent surface tiling method for representing spherical bodies is rst described. Secondly, a simple method which uses image-driven modulation of fractal functions to support the integration of synthetic surface detail with planned topographical features is presented. Finally a deterministic method for the incorporation of randomly placed discrete structures is outlined. A model of the lunar surface is presented as an illustration of these techniques.

We present a system for automatic generation and real-time rendering of forested virtual environments. We produce realistic, eroded landscapes and place tree objects in the scene using ecosystem modelling techniques. The tree objects are generated from L-System models to produce closed triangle meshes. These are used to produce a set of discrete level of detail models, which are converted to triangle strips and saved for use in the scene viewing module. The scene viewer renders the landscape and objects generated in the previous two modules, allowing the user to navigate in the scene. Impostors, discrete level of detail and e#cient use of graphics hardware allow the scene to be viewed with interactive frame-rates for scenes of moderate tree density. 1

In this paper, we propose a flexible noise model for multi-dimensional map synthesis. This model allows the generation of a very varied range of maps, that can be used as perturbation functions, for the generation of color textures, or as bump or displacement maps, for geometric deformation of surface or volume objects.

This paper introduces a possible fractal model for rocks and stones where the model’s emphasis is laid on fast and random generation. The concept is based on the similarity of rock surfaces and terrain surfaces which brought forth the idea of creating rocks with wellresearched landscape and terrain generation algorithms.

The ocean is an important arena in computer visualization. In the offshore industry, virtual environments have been embraced to improve interdisciplinary information sharing, decision making, and more. Convincing natural backdrops not only serve as a benchmark for computer games these days, but are to a higher degree expected elements in professional applications. Apart from being cosmetic selling features, such elements can improve the user's experience and provide intuitive visual cues, e.g. about weather conditions. The student is carrying out his work at Systems in Motion AS (SIM). SIM delivers a high-level scene-graph library, Coin3D, which is built around OpenGL and open to the public. Coin3D is used in the development of several applications targeted at the offshore industry. The proposed problem arises from the desire to integrate a realistic and efficient ocean surface simulator into this library. Problem specification: The problem in focus is to graphically reproduce a typical offshore environment. More specifically, the aim is to realistically simulate and visualize the surface of open seas at real-time rendering rates, using current consumer range hardware. This implies very large water surfaces dominated