Hardware-Accelerated BVH Construction Through Sorting and Reduction

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Solution Overview

Problem

Existing software-based methods for Bounding Volume Hierarchy (BVH) construction incur computational overhead, limit scalability, and fail to fully leverage hardware acceleration capabilities, particularly in real-time or interactive applications.

Innovation Solution

Implementing specialized hardware circuitries for sorting and reduction operations within GPUs to accelerate BVH construction, utilizing parallel processing techniques and minimizing memory access latencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If software-based sorting and reduction operations are used for BVH construction, then implementation flexibility is maintained, but construction time increases significantly and hardware acceleration capabilities are not fully exploited

Engineering Contradiction:
ImproveBVH construction speedVSAvoidhardware circuitry complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces software-based sorting and reduction operations with dedicated hardware circuitry (sorting circuit and reduction circuit). The sorting circuit uses parallel comparison logic to sort primitive centroids along selected axes, while the reduction circuit uses hardware-based prefix sum operations to compute cluster assignments. This substitution of software computation with hardware circuitry directly addresses the contradiction by dramatically improving BVH construction speed while accepting increased hardware complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements self-service through automated axis selection and iterative sorting-reduction operations. The system automatically selects the longest axis for sorting based on bounding box calculations, performs multiple iterations of sorting and reduction without manual intervention, and uses the reduction results to guide subsequent sorting operations. This automation enables the hardware circuitry to efficiently construct BVHs for varying scene geometries without requiring complex external control.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If software-based sorting and reduction processes are used, then ease of implementation is maintained, but scalability is limited and memory management complexity increases

Engineering Contradiction:
ImprovescalabilityVSAvoidimplementation complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent segments the BVH construction process into distinct hardware circuits: a sorting circuit that handles primitive sorting based on centroids, a reduction circuit that computes cluster assignments using prefix sums, and a BVH builder that integrates these operations. This segmentation allows each circuit to be optimized independently and enables the system to handle larger datasets by distributing work across multiple processing units or increasing circuit capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes operational parameters dynamically during BVH construction. The sorting circuit varies the sort axis selection based on the longest dimension of the current primitive set, the reduction circuit adjusts cluster counts based on scene complexity, and the system performs multiple iterations with changing parameters to optimize the hierarchy. This parameter adaptability enables scalability to different scene sizes and geometries.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20250307207A1System and Method for Bounding Volume Hierarchy Construction
Publication Date: 2025.10.02 ADVANCED MICRO DEVICES INC
  • US20250307207A1 patent drawing
  • US20250307207A1 patent drawing
  • US20250307207A1 patent drawing

AI summary

Systems and methods for faster BVH building that requires repeated sorting and partitioning of are described. Specific hardware circuitries are programmed to sort partitioned data and make reductions for each partition. The hardware units perform the initial sorting along a split axis and calculation of bounding box extents. The solutions presented herein improve performance of BVH builds, especially for cases where the geometry is comprised of many small BVH treelets. The most expensive processing steps in BVH construction are delegated to hardware thereby minimizing memory access latencies and increasing overall system efficiencies.