Real-Time Ray Tracing of Micro-Poly Geometry with Hierarchical Level of Detail

Benthin, Carsten; Peters, Christoph

Real-Time Ray Tracing of Micro-Poly Geometry with Hierarchical Level of Detail

Files

v42i8_04_14868.pdf (13.5 MB)

mm1001.mp4 (283.47 MB)

Date

2023

Authors

Benthin, Carsten
Peters, Christoph

Publisher

The Eurographics Association and John Wiley & Sons Ltd.

Abstract

In recent work, Nanite has demonstrated how to rasterize virtualized micro-poly geometry in real time, thus enabling immense geometric complexity. We present a system that employs similar methods for real-time ray tracing of micro-poly geometry. The geometry is preprocessed in almost the same fashion: Nearby triangles are clustered together and clusters get merged and simplified to obtain hierarchical level of detail (LOD). Then these clusters are compressed and stored in a GPU-friendly data structure. At run time, Nanite selects relevant clusters, decompresses them and immediately rasterizes them. Instead of rasterization, we decompress each selected cluster into a small bounding volume hierarchy (BVH) in the format expected by the ray tracing hardware. Then we build a complete BVH on top of the bounding volumes of these clusters and use it for ray tracing. Our BVH build reaches more than 74% of the attainable peak memory bandwidth and thus it can be done per frame. Since LOD selection happens per frame at the granularity of clusters, all triangles cover a small area in screen space.

        @article{10.1111:cgf.14868
,
journal = {Computer Graphics Forum},
title = {{Real-Time Ray Tracing of Micro-Poly Geometry with Hierarchical Level of Detail
}},
author = {Benthin, Carsten and 
Peters, Christoph
},
year = {2023
},
publisher = {The Eurographics Association and John Wiley & Sons Ltd.
},
ISSN = {1467-8659
},
DOI = {10.1111/cgf.14868
}
}