Tobias Hüttner

OpenGL-assisted occlusion culling for large polygonal models

Abstract We present an OpenGL-assisted visibility culling algorithm to improve the rendering performance of large polygonal models. Using a combination of hierarchical model-space partitioning, OpenGL-assisted view-frustum culling, and OpenGL-assisted occlusion culling, we achieve a significantly better performance on general polygonal models than previous approaches. In contrast to these approaches, we only exploit common OpenGL features and therefore, our algorithm is also well suited for low-end OpenGL graphics hardware. Furthermore, we propose a small addition to the OpenGL rendering pipeline to enhance the framebuffers ability for faster and more detailed occlusion queries.

Extending graphics hardware for occlusion queries in OpenGL

For interactive rendering of large polygonal objects, fast visibility queries are necessary to quickly decide whether polygonal objects are visible and need to be rendered. None of the numerous published algorithms provide visibility performance for interactive rendering of large models. In this paper, we propose an OpenGL extension for fast occlusion queries. Added after the depth test stage of the OpenGL rendering pipeline, our algorithm provides fast queries to establish the occlusion of polygonal objects. Furthermore, hardware aspects of this proposal are discussed and possible implementations on two different graphics architectures are presented.

Multiresolution rendering with displacement mapping

In this paper, we present for the first time an approach for hardware accelerated displacement mapping. The displaced surface is generated from a 2D displacement map by remeshing a coarse triangle mesh according to the screen projection of the surface. The remeshing algorithm is implemented in hardware. Filtered access to the displacement map makes our approach competitive with available view dependent multiresolution techniques. The advantage of displacement mapping is the compact representation. A displacement mapped surface consumes together with all filter levels only a fraction of the storage space needed for a hardware compatible representation of an equivalent triangle mesh. A possible design of the displacement mapping rendering pipeline is proposed. Previously described hardware components are used as often as possible. Our approach can be smoothly integrated into all available graphics application programming interfaces. Most existing graphics applications can be extended to the new feature with marginal effort. CR Categories: I.3.1 [Computer Graphics]: Hardware Architecture—Raster display devices I.3.3 [Computer Graphics]: Picture/Image Generation—Bitmap and framebuffer operations, Display algorithms, Viewing algorithms I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling—Curve, surface, solid, and object representations I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism—Color, shading, shadowing, and texture

Fast footprint MIPmapping

Fast Footprint MlPmapping Tobias Hiittner, Wolfgang Strafier WSI/GRIS, University of Tiibingen Mapping textures onto surfaces of computer-generated objects is a technique which greatly improves the realism of their appearance. In this paper, we describe a new method for efficient and fast texture filtering to prevent aliasing during texture mapping. This method, called Fast Footprint MIPmapping, is very flexible and can be adapted to the internal bandwrdth of a graphrcs system. It adopts the prefiltered MIPmap data structure of currently available trilinear MIPmapping implementatrons, but exploits the texels fetched from texture memory in a more optimal manner. Furthermore, like trilinear MIPmapping, fast footprint MIPmapping can easily be realized in hardware. It is sufficient to fetch only eight texels per textured pixel to achieve a significant improvement over classical trilinear MIPmapping. CR Categories: I.3 [1.3.3 Picture/Image Generation]: Antialiasing-Bitmap and framebuffer operationsVrewing algorithms I.3 [1.3.7 Three-Dimensional Graphics and Realism]: Color, shading, shadowing, and texture

Incremental view-dependent multiresolution triangulation of terrain

A view-dependent multiresolution triangulation algorithm is presented for a real-time fly-through. The triangulation of the terrain is generated incrementally on-the-fly during the rendering time. We show that since the view changes smoothly, only a few incremental modifications are required to update the triangulation to a new view. The resulting triangles form a multiresolution Delaunay triangulation which satisfies a predetermined view-dependent error tolerance. The presented method provides a guaranteed-quality mesh since it has control over the global geometric approximation error of the multiresolution view-dependent triangulation.

FlyAway: a 3D terrain visualization system using multiresolution principles

Abstract This paper describes the ideas behind and the development of FlyAway , an environment to handle landscape data interactively. We integrate in this project some aspects of computer graphics that are still open problems concerning high quality landscape rendering. It concerns the usage of multiresolution techniques for viewing-dependent reduction of texture and model complexity and the use of standard graphics libraries for maintaining portability between different kinds of computers and operating systems.

Accelerated rendering in stereo-based projections (poster session)

In this work, we present a new method for displaying stereo scenes, which speeds up the rendering time of complex geometry. We first discuss a scene splitting strategy, allowing us to partition objects to the distant background or the near foreground. Furthermore, wededuce a computation rule for positioning a cutting plane in the scene.