Bounding Volume Hierarchy Reinsertions for Faster Ray Intersection Search

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for optimizing bounding volume hierarchies (BVHs) in ray tracing, such as Meister's approach, face issues with discarding potentially beneficial reinsertions due to conflicts and restricting the tree structure to binary, which limits computational efficiency improvements.

Innovation Solution

A method that allows non-binary reinsertions, retries conflicted reinsertions, and restricts the search to specific hierarchical levels to optimize BVHs, ensuring deterministic allocation and reducing processing burden while enhancing computational efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If binary tree structure is enforced for BVH optimization, then implementation simplicity is maintained, but computational efficiency improvement is limited

Engineering Contradiction:
Improveimplementation simplicityVSAvoidcomputational efficiency improvement
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent segments the rigid binary tree structure into flexible non-binary node structures, allowing nodes to have variable numbers of children based on spatial distribution and SAH optimization criteria. This segmentation enables more adaptive BVH construction while maintaining manageable complexity through systematic node insertion and reinsertion procedures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic node degree flexibility, where nodes can transition from binary to non-binary structures during optimization iterations. The node degree adapts based on spatial relationships and SAH score improvements, allowing the BVH structure to dynamically reconfigure for optimal ray tracing performance rather than being constrained by fixed binary topology.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If all candidate reinsertions are attempted in BVH optimization, then SAH score improvement is maximized, but processing resources and time are excessively consumed

Engineering Contradiction:
ImproveSAH score optimizationVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by selectively processing only promising candidate reinsertions rather than exhaustively evaluating all possible candidates. The system identifies and processes high-potential reinsertions based on heuristic criteria, achieving sufficient SAH optimization without the prohibitive cost of complete enumeration, thus balancing precision with processing time.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the evaluation parameter from exhaustive candidate assessment to selective candidate filtering based on spatial and structural criteria. By modifying which candidates are processed and how they are evaluated, the system achieves effective SAH optimization with reduced computational overhead, transforming the optimization approach from brute-force to intelligent sampling.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If conflicted reinsertions are discarded to maintain tree consistency, then structural integrity is preserved, but potential SAH improvements are lost

Engineering Contradiction:
Improvetree structure integrityVSAvoidSAH score optimization
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent performs preliminary validation of conflicted reinsertions before discarding them, checking whether they can be adapted to work with the current tree structure. By pre-assessing the viability of conflicted candidates and preparing alternative insertion strategies, the system recovers potential SAH improvements that would otherwise be lost, while maintaining structural integrity through controlled conflict resolution.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent converts the harmful effect of conflicted reinsertions into beneficial opportunities for optimization. Instead of simply discarding conflicts, the system analyzes them to identify underlying structural improvements, using the conflicts as signals for potential reorganization opportunities that can lead to better SAH scores while resolving structural inconsistencies.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Manufacturing precision

If full tree search is performed for reinsertion candidates, then optimal BVH configuration is achieved, but processing burden increases significantly

Engineering Contradiction:
ImproveBVH optimization qualityVSAvoidprocessing burden
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by focusing the search for reinsertion candidates on specific regions of the BVH tree where optimization potential exists, rather than uniformly searching the entire tree. By identifying and concentrating computational effort on locally promising areas based on spatial distribution and structural characteristics, the system achieves effective optimization with reduced processing burden.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent performs preliminary identification and filtering of promising reinsertion candidate regions before conducting detailed optimization searches. By pre-marking areas with high optimization potential and excluding low-priority regions, the system significantly reduces the effective search space and processing burden while maintaining optimization quality in critical areas.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS12456251B2Formation of bounding volume hierarchies
Publication Date: 2025.10.28 IMAGINATION TECH LTD
  • US12456251B2 patent drawing
  • US12456251B2 patent drawing
  • US12456251B2 patent drawing

AI summary

A method performed by a graphics processor searches for a candidate reinsertion for each of a plurality of input nodes of a current bounding volume hierarchy (BVH) which would move the input node from an old parent to a new parent, and which would reduce an expected computational cost of searching the BVH for a ray intersection; and performs a first update to update the current BVH with one or more selected reinsertions from among the candidates. The selection comprises a conflict check to determine whether any group of the candidates would affect a same part of the current BVH, and if so selecting only one of the group to include in the first update. At least one of the iterations further comprises, after the first update, performing a second update within the same iteration to update the current BVH with another of said group.