High Quality Volume Rendering

Joshua J. Lawrence, MSc thesis 1998

Abstract

While volume rendering is a well researched topic, many existing renderers sacrifice accuracy for execution speed. The research in this thesis aims for quality over speed. We introduce a ray-casting method that retains fidelity to the emis-sion- absorption volume model, using a high accuracy integration approach. The integration formula handles piecewise linear emission and piecewise constant absorption, and correctly calculates the attenuation of light within each integration step, unlike many common methods. For efficient rendering, a pointerless octree representation of the volume was used, with each ray performing a leaf by leaf traversal. Rays are able to traverse from leaf to leaf quickly without climbing the tree or performing a search, as in other methods. We examine the quality of the renderer when used with a number of medical data sets, and discuss the advantages of a high quality rendering for image generation. We find that it is possible to generate high resolution images from reasonably sized data sets using the modest resources of current desktop personal computers. High order methods for integration prove to give greater accuracy for the same calcula-tion time as standard methods.

Thesis

Images

High resolution images