Half-precision Floating-point Ray Traversal

Matias Koskela, Timo Viitanen, Pekka Jääskeläinen, Jarmo Takala

2016

Abstract

Ray tracing is a memory-intensive application. This paper presents a new ray traversal algorithm for bounding volume hierarchies. The algorithm reduces the required memory bandwidth and energy usage, but requires extra computations. This is achieved with a new kind of utilization of half-precision floating-point numbers, which are used to store axis aligned bounding boxes in a hierarchical manner. In the traversal the ray origin is moved to the edges of the intersected nodes. Additionally, in order to retain high accuracy for the intersection tests the moved ray origin is converted to the child’s hierarchical coordinates, instead of converting the child’s bound coordinates into world coordinates. This means that both storage and the ray intersection tests with axis aligned bounding boxes can be done in half-precision. The algorithm has better results with wider vector instructions. The measurements show that on a Mali-T628 GPU the algorithm increases frame rate by 3% and decreases power consumption by 9% when wide vector instructions are used.

Paper Citation

in Harvard Style

Koskela M., Viitanen T., Jääskeläinen P. and Takala J. (2016). Half-precision Floating-point Ray Traversal . In Proceedings of the 11th Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - Volume 1: GRAPP, (VISIGRAPP 2016) ISBN 978-989-758-175-5, pages 171-178. DOI: 10.5220/0005728001690176

in Bibtex Style

@conference{grapp16,
author={Matias Koskela and Timo Viitanen and Pekka Jääskeläinen and Jarmo Takala},
title={Half-precision Floating-point Ray Traversal},
booktitle={Proceedings of the 11th Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - Volume 1: GRAPP, (VISIGRAPP 2016)},
year={2016},
pages={171-178},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0005728001690176},
isbn={978-989-758-175-5},
}

in EndNote Style

TY - CONF
JO - Proceedings of the 11th Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - Volume 1: GRAPP, (VISIGRAPP 2016)
TI - Half-precision Floating-point Ray Traversal
SN - 978-989-758-175-5
AU - Koskela M.
AU - Viitanen T.
AU - Jääskeläinen P.
AU - Takala J.
PY - 2016
SP - 171
EP - 178
DO - 10.5220/0005728001690176