The Prioritized-Layered Projection Algorithm for Visible Set Estimation

Prioritized-Layered Projection (PLP) is a technique for fast rendering of high depth complexity scenes. It works by estimating the visible polygons of a scene from a given viewpoint incrementally, one primitive at a time. It is not a conservative technique, instead PLP is suitable for the computation of partially correct images for use as part of time-critical rendering systems. From a very high level, PLP amounts to a modification of a simple view-frustum culling algorithm, however, it requires the computation of a special occupancy-based tessellation, and the assignment to each cell of the tessellation a solidity value, which is used to compute a special ordering on how primitives get projected. In this paper, we detail the PLP algorithm, its main components and implementation. We also provide experimental evidence of its performance, including results on two types of spatial tessellation (using octreeand Delaunay-based tessellations), and several datasets. We also discuss several extensions of our technique. Index Terms visibility culling, approximate visibility, time-critical rendering, occlusion culling, visible set, spatial tessellation