Authors:
Julius Ikkala
;
Tuomas Lauttia
;
Pekka Jääskeläinen
and
Markku Mäkitalo
Affiliation:
Tampere University, Tampere, Finland
Keyword(s):
Computer Graphics, Real-Time Rendering, Ray Tracing, Data Structures.
Abstract:
We propose “Hierarchical Bitmask Implicit Grids”, a novel, memory-efficient spatial index data structure for querying bounding volumes based on a contained point, targeting real-time use cases on GPUs. Like grid structures based on 3D arrays, implicit grids allow for nearly array-like direct lookups of cells without traversal through a spatial tree structure. However, the space complexity of this structure is O(n) with respect to resolution as opposed to O(n 3 ), which allows for dramatically higher resolutions than would be feasible with a 3D array. We demonstrate the effectiveness of this data structure by applying it to two example use cases: light culling and decal rendering. We measure both cases with ray tracing and multi-view rendering. We show that with tens of thousands of entries, our data structure can be built in 0.1–0.2 milliseconds, being ∼ 2.9x faster than the compared state-of-the-art decal method and orders of magnitude faster than dense 3D arrays, while delivering a
t least similar or even up to doubled rendering performance.
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