Silhouette Partitioning for Height Field Ray Tracing

Abstract

This paper presents parallel algorithm to ray trace height fields that is suitable for recent GPUs. No data preprocessing is needed, therefore this algorithm can render dynamic height fields. Partitioning binary tree for screen space is calculated each frame. It takes silhouettes of height field regions as partitioning curves. Ray tracing step uses binary search in this silhouette tree to find height field coordinates of pixel visible at given screen coordinates. Presented algorithm takes fixed amount of samples into consideration to produce value in each pass, therefore worst-case scenario is deterministic. This enables the implementation for GPUs having limited dependent texture lookups.