Template-based rendering of run-length- encoded volumes

Template-based volume rendering is a technique to accelerate volume ray casting. It does not trade off image quality for rendering speed. However, it still falls short of interactive manipulation of volume data, mainly owing to the ray-by-ray volume access pattern and the long ray path in the transparent regions. In this paper we present an object-order template-based volume rendering method that uses run-length encoding to enable skipping highly transparent regions. We present three algorithms, one for each principal axis direction. By combining the advantages of object-order volume traversal and run-length encoded volumes, the algorithms achieve high quality rendering in a much shorter time than the original template-based volume rendering. © 1998 John Wiley & Sons, Ltd.