PI: Charles Hansen, School of Computing, University of Utah Co-PI: Sarah Creem-Regehr, Dept. of Psychology, University of Utah
Direct volume rendering has proven to be an effective and flexible visualization method for interactive exploration and analysis of 3D scalar fields. The ability to analyze 3D volumetric data sets is crucial to the success of large-scale simulation. This research will increase the analysis and understanding of volumetric data through more faithful rendering methods that take into consideration the interaction of light with the volume itself. The research will investigate a new interactive volume shading method that incorporates global illumination effects and is robust for lighting of volumetric materials. Such an illumination model will more effectively bring out data characteristics for analysis and will be more effective for multi-field visualization than current shading methods.
While direct volume rendering is widely used in visualization applications, most, if not all, of these applications render (semi-transparent) surfaces lit by an approximation to the Phong local surface shading model. This shading model renders such surfaces but it does not provide sufficient lighting characteristics for good spatial acuity. To improve an illumination model for volume rendering, it is necessary to investigate approximations to global illumination using novel volumetric shading techniques. This investigation is producing in an effective model that captures physical effects of classified volumetric data such as back-scattering, inter/intra-surface illumination, and better forward scattering. The success of this project is being measured by applying the new techniques to multi-field visualization in the areas of computational combustion, bio-electric field simulation, multi-modal medical imaging, and scanned multi-modal data for non-destructive testing in which analysis through direct volume rendering is an appropriate visualization methodology. The effectiveness of these new methods will be tested through user studies that will include both perceptual psychologists familiar with perception testing in computer graphics and domain scientists.
