Half-precision Floating-point Ray Traversal

Matias Koskela, Timo Viitanen, Pekka Jääskeläinen, Jarmo Takala

    Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

    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 pow er consumption by 9% when wide vector instructions are used.
    Original languageEnglish
    Title of host publicationProceedings of the 11th Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications
    Place of PublicationRome, Italy
    PublisherSCITEPRESS
    Pages169-176
    Number of pages8
    ISBN (Electronic)978-989-758-175-5
    DOIs
    Publication statusPublished - 29 Feb 2016
    Publication typeA4 Article in a conference publication
    EventINTERNATIONAL CONFERENCE ON COMPUTER GRAPHICS THEORY AND APPLICATIONS -
    Duration: 1 Jan 1900 → …

    Conference

    ConferenceINTERNATIONAL CONFERENCE ON COMPUTER GRAPHICS THEORY AND APPLICATIONS
    Period1/01/00 → …

    Keywords

    • Ray Tracing
    • Bounding Volume Hierarchy
    • Half-precision Floating-point Numbers

    Publication forum classification

    • Publication forum level 1

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