In this masters thesis by Marcin Jdrzejewski, ray tracing is implemented on the GPU to accelerate computation of sound paths between sound sources and receivers. Each ray averages 16-20 wall reflections, and those rays that intersect a sphere approximating the receiver are included in an echogram that is used in the auralization process. Typically 4096 rays are used, but the application can run in real time with up to 64K rays. A demo application, article and some movies can be downloaded from the following link. (Computation of room acoustics on a GPU.)

From a press release at www.BionicFX.com: “BionicFX announces a revolutionary technology for music production that turns NVIDIA video cards into audio effects processors. Audio Video Exchange (AVEX) converts digital audio into graphics data, and then performs effect calculations using the 3D architecture of the GPU. The latest video cards from NVIDIA are capable of more than 40 gigaflops of processing power compared to less than 6 gigaflops on Intel and AMD CPUs. AVEX represents a major technological achievement that allows music hobbyists and professional artists to run studio quality audio effects at high sample rates on their desktop computer. (Press Release: “Revolutionary Programming and Innovation uses GPU as Powerful Audio Effect Processor”)

TyphoonLabs have published the Fractal Explorer v1.0, an application to explore the most common fractals (such as Julia sets, Mandelbrot sets, and some alternate Julia planes) using the GPU to compute them. It can easily be extended with new fractals written in the OpenGL Shading Language. (TyphoonLabs Fractal Explorer v1.0)

NVIDIA recently released an updated version of FX Composer with support for Shader Model 3.0 and tons of new sample shaders. The latest version also includes many developer-requested UI improvements, support for NV4x GPU performance analysis, and a beta SDK that allows developer to write their own automation scripts, importers/exporters, etc. The best way to view all the sample shaders is by downloading the latest NVIDIA SDK and looking at the “Effects” tab where you will find descriptions and screenshots of 250+ effects. (FX Composer Homepage)

Cg Release 1.3 Beta 2 has been released with support for the latest GeForce 6 Series (NV4X) GPUs. This version of Cg offers the following features and improvements:

• New vp40 profile, which enables texture sampling from within vertex programs
• New fp40 profile, which provides a robust branching model in fragment programs, and support for output to multiple draw buffers (“MRTs”)
• Support for writing more than one color output (i.e., MRTs) in the arbfp1 and ps_2* profiles
• New semantics to access OpenGL fixed-function state vectors from within ARB_vertex_program and ARB_fragment_program
• New “-fastprecision” option for arbfp*, fp30, and fp40 profiles, to use reduced precision storage (fp16) when appropriate
• Support for 16 profiles

(http://developer.nvidia.com/object/cg_toolkit.html)

This paper by Fan et. al. at Stony Brook University presents the use of a cluster of commodity GPUs for high performance scientific computing. As an example application, they have developed a parallel flow simulation using the lattice Boltzmann model (LBM) on a GPU cluster and have simulated the dispersion of airborne contaminants in the Times Square area of New York City. Using 30 GPU nodes, their simulation can compute a 480 x 400 x 80 LBM in 0.31 second/step, a speed which is 4.6 times faster than that of their previous CPU cluster implementation. Besides the LBM, the paper also discusses other potential applications of the GPU cluster, such as cellular automata, PDE solvers, and FEM. (Zhe Fan, Feng Qiu, Arie Kaufman, Suzanne Yoakum-Stover, GPU Cluster for High Performance Computing, To Appear in Proceedings of the ACM/IEEE SuperComputing 2004 (SC’04), November, 2004)

Linear expressions constitute one of the most basic operations in scientific computations. This paper by proposes a SIMD code optimization technique that enables efficient shader codes to be generated for evaluating linear expressions. Performance can be improved considerably by efficiently packing arithmetic operations into four-wide SIMD instructions through reordering of the operations in linear expressions. We demonstrate that this technique can be used effectively for programming both vertex and pixel shaders for a variety of mathematical applications. (SIMD Optimization of Linear Expressions for Programmable Graphics Hardware. C. Bajaj, I. Ihm, J. Min, and J. Oh)

Ne@tware Player 2004 supports the latest DirectX 9.0c graphic and media technologies. It allows you to design and watch visual special effects in real-time. The Shader Model 3.0 and High Level Shader Language (HLSL) support make Ne@tware Player a shader development platform for video processing in Graphic Processing Unit as well. Fullscreen, Multithread Video Engine, Action Mapper, and International Languages are other new features. (http://www.neatware.com/player/)

New versions of the NVIDIA SDK and FX Composer with Shader Model 3.0 support are now available. SDK 8.0 includes hundreds of all-new Shader Model 3.0 code samples and effects, including three new GPGPU code samples:

• GPGPU Fluid, a fast, realistic fluid simulation
• GPGPU Disease, a creepy dynamic “disease” effect based on chemical reaction-diffusion
• GPU Particles, a fast particle system that can simulate 1 million particles at 20 fps on GeForce 6800

Also included in the SDK is the GPU Gems chapter “Fast Fluid Dynamics Simulation on the GPU”. Links to these code samples have been added to the GPGPU developer page.

Following the success of GPU Gems: Programming Techniques, Tips, and Tricks for Real-Time Graphics NVIDIA have decided to produce a second GPU Gems volume in order to showcase the best new ideas and techniques for the latest programmable GPUs. Tentatively titled GPU Gems II: Techniques for Graphics and Compute Intensive Programming, this book will be edited by Matt Pharr, software engineer at NVIDIA.

NVIDIA are looking for ideas from developers who are using GPUs in new ways to create stunning graphics and cutting-edge applications. Chapters should present techniques and ideas that are broadly useful to GPU programmers and can be integrated into their applications. GPU Gems II will have an increased focus on chapters exploring non-graphics applications of the computational capabilities of GPU hardware.

To participate, read the submission guidelines and send an e-mail to articlesubmissions@nvidia.com with your proposed chapter title as the subject line, and the required description in the e-mail body. The deadline for submissions is Monday, August 16, 2004.