*Interactive methods for effective particle visualization

Particle-based simulation methods are used to model complex phenomena in many computational science and engineering applications. Effective visualization of the resulting state communicates subtle changes in the three-dimensional structure, spatial organization, and qualitative trends within the data as a simulation evolves, as well as enabling easier navigation and exploration of the data through interactivity. As particle-based simulations continue to grow in size and complexity, effective visualization becomes increasingly problematic. The sheer size of these datasets make interactive visualization a difficult task, while the intricacies of complex data are difficult to convey sensibly.;This dissertation combines and extends knowledge in computer graphics, scientific visualization, and visual perception to enhance the ability to efficiently and effectively visualize particle-based simulation data. We first introduce two interactive visualization algorithms that render large, time-varying particle datasets at highly interactive rates on current and upcoming desktop computing platforms. Then, to motivate the use of effects from global illumination in particle visualization, we describe a psychophysical user study that examines the impact of two advanced shading models on the ability to detect subtle differences between particle configurations. Finally, we introduce two algorithms that make the use of effects from global illumination practical for an interactive particle visualization process.;The results of this research demonstrate the feasibility of rendering large, time-varying particle datasets at highly interactive rates on desktop computer systems. The interactive visualization algorithms improve performance and make interactive systems more accessible. This dissertation also demonstrates both the importance and feasibility of using advanced shading models in an interactive particle visualization process. The user study shows that effects from global illumination can be perceptually beneficial, while the practical global illumination algorithms demonstrate that advanced shading models can be used in an interactive setting. The results show that the proposed algorithms enhance an investigator's ability to perform data analysis and feature detection tasks while maintaining the ability to interrogate large, time-varying datasets at interactive rates.