Techniques for Visualizing Time-Varying Volume Data

This chapter describes how time-varying volume data can be efficiently rendered to achieve interactive visualization, with a focus on employing data encoding, hardware acceleration, and parallel pipelined rendering. The chapter provides a survey of encoding methods for time-varying volume data. Modern PC graphics cards can be used to render volume data at highly interactive rates. When rendering time-varying data, it is crucial to accelerate the loading of each time-step of the data into the video memory from either main memory or disk. A hardware decoding approach makes it possible to transport and render a much smaller, compressed version of the data instead, which enables interactive exploration in the spatial and temporal domains. Most rendering calculations can be straightforwardly parallelized to increase rendering rates while maintaining high image quality, but the I/O issue must be addressed so that the volume data and image transfer rate can keep up with the rendering rate. A pipelined approach coupled with image compression is demonstrated to reach the highest possible efficiency.