This work is part of a Masters thesis by Konrad Pietras of Technical University of Lodz, Poland. The method uses a neural network, implemented in a vertex program, for approximating the light model described in “Display of The Earth Taking into Account Atmospheric Scattering” by Nishita et al., SIGGRAPH 1996. (GPU-based perceptron used for 4-dimensional texture lookup)

## GPU-based multi-layer perceptron as efficient method for approximating complex light models in per-vertex lighting

April 17th, 2005## A Lighting Model for General Participating Media

March 21st, 2005Efficient and visually compelling reproduction of effects due to multiple scattering in participating media remains one of the most difficult tasks in computer graphics. Although several fast techniques were recently developed, most of them work only for special types of media (for example, uniform or sufficiently dense) or require extensive precomputation. In this paper we present a lighting model for the general case of inhomogeneous medium and demonstrate its implementation on programmable graphics hardware. It is capable of producing high quality imagery at interactive frame rates with only mild assumptions about medium scattering properties and a moderate amount of simple precomputation. (A Lighting Model for General Participating Media. Kyle Hegeman, Michael Ashikhmin and Simon Premoze. Accepted for publication. Proceedings of ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, April 2005.)

## Hardware Efficient PDE Solvers in Quantized Image Processing

March 21st, 2005This thesis by Robert Strzodka describes the design of robust quantized schemes and their hardware efficient implementation on data-stream-based architectures for PDE-based image processing. The focus lies on enhancing both performance and accuracy by an efficient use of appropriate hardware resources. Quantized schemes which, despite roundoff errors, preserve the qualitative behavior of the continuous models are constructed, and examined on different GPUs, a FPGA and a reconfigurable array processor. The pros and cons of the hardware designs and the memory gap problem are discussed in detail. (Hardware Efficient PDE Solvers in Quantized Image Processing. Robert Strzodka. PhD thesis, University of Duisburg-Essen, 2004.)

## Interactive marker-less tracking of human limbs

March 21st, 2005This paper by Rao et al. at UNC Charlotte describes an algorithm to track human limbs at interactive rates without using markers. 3d point cloud data is derived from a modified visual hull algorithm. This data is fed into a particle filtering algorithm that runs on the GPU. The tracking system runs at interactive rates. (Interactive marker-less tracking of human limbs. Rao S., Hodges L.F *to be submitted to Transactions on Visualization and Computer Graphics*.)

## Fourier Volume Rendering on the GPU Using a Split-Stream FFT

March 1st, 2005This paper by Jansen et al. describes how to utilize current commodity graphics hardware to perform Fourier volume rendering directly on the GPU. The paper presents a novel implementation of the Fast Fourier Transform: This Split-Stream-FFT maps the recursive structure of the FFT to the GPU in an efficient way. Additionally, high-quality resampling within the frequency domain is discussed. The implementation enables visualization of large volumetric data sets at interactive frame rates on a mid-range computer system. (Fourier Volume Rendering on the GPU Using a Split-Stream FFT)

## GPU Gems 2 Sample Chapter #2 Released

February 17th, 2005A second GPU Gems 2 sample chapter, Streaming Architectures and Technology Trends (Chapter 29), by John Owens is now available. The first sample chapter Per-Pixel Displacement with Distance Functions (Chapter 8), was released last week.

## “Simulation Practice and Theory” Special Issue on Programmable Graphics Hardware

February 9th, 2005A Special Issue of the Elsevier Journal “Simulation Practice and Theory” about Programmable Graphics Hardware is planned for 2005. Authors of papers which explore simulation studies and algorithms utilizing graphics hardware are invited to participate in the special issue. Please see the Call for Papers for more information.

## Two New GPU Ray Tracing Projects

January 29th, 2005We received news simultaneously from the developers of two new GPU ray tracers. Both projects are graduate-level thesis projects. One, called GPU-RT, is developed by Martin Christen and supports .3DS format meshes, multiple materials, and implements acceleration data structures. GPU-RT runs on NVIDIA GeForce 6 Series GPUs under D3D/HLSL and OpenGL/GLSL, and is available on SourceForge.net. The other project, “Ray Tracing on Programmable Graphics Hardware”, is by Filip Karlsson and Carl Johan Ljungstedt of Chalmers University of Technology. The thesis describes, among other things, how proximity clouds can be used to accelerate ray tracing on the GPU. (1. GPU-RT, Diploma Thesis by Martin Christen. 2. “Ray Tracing on Programmable Graphics Hardware”, Masters Thesis by Filip Karlsson and Carl Johan Ljungstedt.)

## GPGPU Course at the University of Pennsylvania, Spring 2005

January 19th, 2005Suresh Venkatasubramanian will be teaching a GPGPU class at the University of Pennsylvania in Spring 2005. The class, titled “GPU Programming and Architecture” will focus on the stream programming abstraction of the GPU, and will cover the basic tools and techniques for designing and implementing algorithms for general purpose computations on the GPU. (UPenn GPGPU Course)

## Fred Brooks calls GPGPU “…one of the most exciting areas in Computer Architecture today”

January 5th, 2005UNC’s Professor Frederick P. Brooks, Jr., who coined the term “Computer Architecture”, received the 2005 ACM/IEEE Computer Society Eckert-Mauchly Award for outstanding contributions to the field of computer and digital systems architecture. In his award acceptance speech, Dr. Brooks stated that GPUs are “…very powerful scientific computers installed in many homes… I think exploring that design space and its utilization… is one of the most exciting areas in computer architecture today.” (Frederick P. Brooks, Jr. 2005 Eckert-Mauchly Award acceptance speech. Streaming Video Links)