IEEE Visualization 2008 Tutorial #1002

Timo Ropinski, Christof Rezk-Salama, Markus Hadwiger, Patric Ljung

Tutorial Description

We will present an in-depth tutorial on GPU-based ray-casting approaches to volume visualization, including acceleration techniques, efficient memory management and advanced illumination models. Participants will learn how to leverage the new features of modern commodity graphics hardware to implement advanced illumination techniques for high-quality volume rendering applications supporting improved spatial comprehension. Thus they should be able to target new research directions towards visualization techniques exploiting novel shading models as well as to improve the existing advanced shading models.

The tutorial starts with an introduction to the basic principles of GPU-based volume ray-casting, including useful optimization techniques highly benefitial for advanced illumination models. After these areas have been covered existing interactive illumination models for GPU-based volume ray-casting are explained in detail, by considering their contribution to the image understanding process.

Level of the Tutorial

Intermediate to advanced. The tutorial is aimed at scientific researchers and developers of
visualization tools. Course participants should have basic programming skills and should be familiar with graphics hardware
and shading languages. We will assume a basic knowledge regarding volume data as well as interactive volume rendering techniques. Furthermore, a basic understanding of GPU-based rendering techniques is required.

Slides & Tutorial Notes

Timo Ropinski: Introduction

Markus Hadwiger: Basics

• Application Areas for Volume Rendering
• Benefits and Drawbacks of Ray-Casting
• GPU-based Volume Ray-Casting
• Space Leaping and Early Ray Termination
• Memory Management
• Multiresolution LOD and Adaptive sampling

Timo Ropinski: Light Interaction

• Light Transport and Illumination Models
• Local Volume Illumination
• Specular Reflections through Ray-Tracing
• Soft vs. Hard Shadows
• Semi-Transparent Shadows with Deep Shadow Maps
• Simulation of Color Bleeding

Patric Ljung: Ambient Occlusion

• Ambient Occlusion for Isosurfaces
• Local Ambient Occlusion (DVR)
• Dynamic Ambient Occlusion (DVR)

Christof Rezk-Salama: Scattering

• Monte-Carlo Integration
• Single versus Multiple Scattering
• Translucency
• Monte-Carlo Scattering
• First-order Multiple Scattering
• Scattering with Deep Shadow Maps

Instructors Background

Markus Hadwiger

Markus Hadwiger is a senior researcher at the VRVis Research Center in Vienna, Austria. He received his Ph.D. in computer science from the Vienna University of Technology in 2004, and has been a researcher at VRVis since 2000, working in the Basic Research on Visualization group and the Medical Visualization group (since 2004). He has been involved in several courses and tutorials about volume rendering and visualization at ACM SIGGRAPH, IEEE Visualization, and Eurographics. He is a co-author of the book Real-Time Volume Graphics published by A K Peters.

Patric Ljung

Patric Ljung joined in 2007 Siemens Corporate Research in Princeton, NJ, where he works as a Research Scientist in the Imaging Architectures group. He received 2006 his PhD in Scientific Visualization from Linköping University, Sweden and graduated with honors in 2000 his MS in Information Technology from Linköping University. Between 1989 and 1995 he worked as a software engineer with embedded and telecom systems involving software architectures, graphical user interfaces, voice-mail systems, communication protocols, network and interprocess communication, compilers.

Dr. Ljung has published several papers in international conferences and journals including IEEE Visualization, Eurographics conferences, IEEE TVCG and others, on volume rendering of large medical data sets, GPU-based ray-casting of multiresolution data sets. One important
focus area has been Virtual Autopsies for forensic pathology. His current research interest is in advanced illumination and shading techniques, software architectures for extensible graphics, and management and rendering of large medical data sets.

Christof Rezk-Salama

Christof Rezk-Salama has received a PhD from the University of Erlangen-Nuremberg as a scholarship holder of the graduate college 3D Image Analysis and Synthesis. He has worked as a research engineer for the R&D department of Siemens Medical Solutions. Since October 2003 he is working as an assistant professor at the Computer Graphics Group of the University of Siegen, Germany.

The results of his research have been presented at international conferences, including ACM SIGGRAPH, IEEE Visualization, Eurographics, MICCAI and Graphics Hardware. He is regularly holding lectures, courses and seminars on computer graphics, scientific visualization, character animation and graphics programming.

He has gained practical experience in applying computer graphics to several scientific projects in medicine, geology and archaeology. Christof Rezk-Salama has released the award winning open-source project OpenQVis and is a co-author of the book Real-Time
Volume Graphics.

Timo Ropinski

Timo Ropinski is a postdoctoral researcher working in the field of medical volume visualization. After receiving his PhD in 2004 from the University of Münster, he became a project leader within the collaborative research center SFB 656, a cooperation between researchers from medicine, mathematics, chemistry, physics and computer science. His research is focused on interactive aspects in medical volume visualization with the goal to make these techniques more accessible. He is regularly holding lectures and seminars on computer graphics and scientific visualization, and is the initiator of the Voreen open source project, in which a flexible volume rendering framework is developed. The results of his scientific work have been published in various international conferences including Eurographics, IEEE Visualization, IEEE VR, VMV and others.

Links

Book on Real-Time Volume Graphics: www.real-time-volume-graphics.org

Volume Graphics Course at Siggraph 2004: www.vrvis.at/via/resources/course-volgraphics-2004/

Volumeshop: www.volumeshop.org

Voreen - Volume Rendering Engine: www.voreen.org