Oliver G. Staadt

blue-c: a spatially immersive display and 3D video portal for telepresence

In this paper, we report ongoing work in a new project, The Blue-C. The goal of this project is to build a collaborative, immersive virtual environment which will eventually integrate real humans, captured by a set of video cameras. Two Blue-C.s will be interconnected via a high-speed network. This will allow for bi-directional collaboration and interaction between two persons sharing virtual spaces. The video streams are used for both texture and geometry extraction. We will generate a 3-D light field inlay enriched with the reconstructed geometry, which will be integrated into the virtual environment. The design and construction of the Blue-C. environment, including both hardware and software, is an interdisciplinary effort with participants from the departments of computer science, architecture, product development, and electrical engineering. Parallel to the development of the core system, we are designing new applications in the areas of computer aided architectural design, product reviewing, and medicine, which will highlight the versatility of the Blue-C.

A Survey of Large High-Resolution Display Technologies, Techniques, and Applications

Continued advances in display hardware, computing power, networking, and rendering algorithms have all converged to dramatically improve large high-resolution display capabilities. We present a survey on prior research with large high-resolution displays. In the hardware configurations section we examine systems including multi-monitor workstations, reconfigurable projector arrays, and others. Rendering and the data pipeline are addressed with an overview of current technologies. We discuss many applications for large high-resolution displays such as automotive design, scientific visualization, control centers, and others. Quantifying the effects of large high-resolution displays on human performance and other aspects is important as we look toward future advances in display technology and how it is applied in different situations. Interacting with these displays brings a different set of challenges for HCI professionals, so an overview of some of this work is provided. Finally, we present our view of the top ten greatest challenges in large highresolution displays.

3D video recorder

We present the 3D video recorder, a system capable of recording, processing, and playing three-dimensional video from multiple points of view. We first record 2D video streams from several synchronized digital video cameras and store pre-processed images to disk. An off-line processing stage converts these images into a time-varying three-dimensional hierarchical point-based data structure and stores this 3D video to disk. We show how we can trade-off 3D video quality with processing performance and devise efficient compression and coding schemes for our novel 3D video representation. A typical sequence is encoded at less than 7 megabits per second at a frame rate of 8.5 frames per second. The 3D video player decodes and renders 3D videos from hard-disk in real-time, providing interaction features known from common video cassette recorders, like variable-speed forward and reverse, and slow motion. 3D video playback can be enhanced with novel 3D video effects such as freeze-and-rotate and arbitrary scaling. The player builds upon point-based rendering techniques and is thus capable of rendering high-quality images in real-time. Finally, we demonstrate the 3D video recorder on multiple real-life video sequences.

The blue-c distributed scene graph

We present a distributed scene graph architecture for use in the blue-c, a novel collaborative immersive virtual environment. We extend the widely used OpenGL Performer toolkit to provide a distributed scene graph maintaining full synchronization down to vertex and texel level. We propose a synchronization scheme including customizable, relaxed locking mechanisms. We demonstrate the functionality of our toolkit with two prototype applications in our high-performance virtual reality and visual simulation environment.

Spatialized audio rendering for immersive virtual environments

We present a spatialized audio rendering system for the use in immersive virtual environments. The system is optimized for rendering a sufficient number of dynamically moving sound sources in multi-speaker environments using off-the-shelf audio hardware. Based on simplified physics-based models, we achieve a good trade-off between audio quality, spatial precision, and performance. Convincing acoustic room simulation is accomplished by integrating standard hardware reverberation devices as used in the professional audio and broadcast community. We elaborate on important design principles for audio rendering as well as on practical implementation issues. Moreover, we describe the integration of the audio rendering pipeline into a scene graph-based virtual reality toolkit.

Velocity-Aligned Discrete Oriented Polytopes for Dynamic Collision Detection

We propose an acceleration scheme for many-body dynamic collision detection at interactive rates. We use the Velocity-Aligned Discrete Oriented Polytope (VADOP), a tight bounding volume representation that offers fast update rates and which is particularly suitable for applications with many fast-moving objects. The axes selection that determines the shape of our bounding volumes is based on spherical coverings. We demonstrate that we can robustly detect collisions that are missed by pseudodynamic collision detection schemes with even greater performance due to substantial collision pruning by our bounding volumes.

A survey and performance analysis of software platforms for interactive cluster-based multi-screen rendering

We present a survey of different software architectures designed to render on a tiled display. We provide an in-depth analysis of three selected systems, including their implementation of data distribution, sort-first rendering, and overall usability. We use various test cases to analyze the performance of these three systems.

A practical system for laser pointer interaction on large displays

Much work has been done on the development of laser pointers as interaction devices. Typically a camera captures images of a display surface and extracts a laser pointer dot location. This location is processed and used as a cursor position. While the current literature well explains such a system, we feel that some important practical concerns have gone unaddressed. We discuss the design of such a tracking system, focusing on key practical implementation details. In particular we present a robust and efficient dot detection algorithm that allows us to use our system under a variety lighting conditions, and allows us to reduce the amount of image parsing required to find a laser position by an order of magnitude.

Enabling scientific workflows in virtual reality

To advance research and improve the scientific return on data collection and interpretation efforts in the geosciences, we have developed methods of interactive visualization, with a special focus on immersive virtual reality (VR) environments. Earth sciences employ a strongly visual approach to the measurement and analysis of geologic data due to the spatial and temporal scales over which such data ranges. As observations and simulations increase in size and complexity, the Earth sciences are challenged to manage and interpret increasing amounts of data. Reaping the full intellectual benefits of immersive VR requires us to tailor exploratory approaches to scientific problems. These applications build on the visualization methods strengths, using both 3D perception and interaction with data and models, to take advantage of the skills and training of the geological scientists exploring their data in the VR environment. This interactive approach has enabled us to develop a suite of tools that are adaptable to a range of problems in the geosciences and beyond.

PC Clusters for Virtual Reality

In the late 90’s the emergence of high performance 3D commodity graphics cards opened the way to use PC clusters for high performance Virtual Reality (VR) applications. Today PC clusters are broadly used to drive multi projector immersive environments. In this paper, we survey the different approaches that have been developed to use PC clusters for VR applications. We review the most common software tools that enable to take advantage of the power of clusters. We also discuss some new trends.