Article Info
| Title |
An Efficient Parametric Algorithm for Octree Traversal. |
| Authors |
J. Revelles, C. Ureña, M. Lastra. |
| Published in |
Proceedings of 8th International Conference on Computer Graphics and Visualization'2000
(WSCG'2000 Conference Proceedings)
Plzen (Czech Republic)
February 7-9, 2000. ISBN 80-7082-612-6, ISBN 80-7082-614-6 |
Abstract
An octree is a well known hierarchical spatial structure which is widely used in Computer Graphics algorithms. One of the most frequent operations is the computation of the octree voxels intersected by a straight line. This has a number of applications, such as ray-object intersection tests speed-up and visualisation of hierarchical density models by ray-casting. Several methods have been proposed to achieve this goal, which differ in the order in which intersected voxels are visited. In this paper we introduce a new top-down parametric method. The main difference with previously proposed methods is related to descent movements, that is, the selection of a child sub-voxel from the current one. This selection, as the algorithm, is based on the parameter of the ray and comprises simple comparisons. The resulting algorithm is easy to implement, and efficient when compared to other related top-down and bottom-up algorithms for octrees. Finally, a comparison with Kelvin's method for binary trees is presented.
Article document
Errata
Kalle Rutanen
posted to comp.graphics.algorithms an error in table 1 on page 4. Bits corresponding to X and Z have been swaped, that is, numbers 0 and 2 should be swapped where they appear in the table (thanks a lot to Kalle)