Density-Aware Stochastic Subsets for BVH Construction

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Solution Overview

Problem

Ray tracing techniques, particularly in graphics processing, face challenges with resource-intensive computations and high latency in constructing bounding volume hierarchies (BVHs) due to the need for exhaustive traversal and intersection operations, which hinder real-time performance.

Innovation Solution

The implementation of density-aware stochastic subsets for improved importance sampling, which selectively samples a representative subset of primitives to accelerate BVH construction and reduce latency, using techniques like on-demand builders and meshlet compression to optimize ray traversal and intersection processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If exhaustive traversal and intersection operations are performed to construct BVH, then rendering accuracy is improved, but construction time and resource consumption increase

Engineering Contradiction:
Improverendering accuracyVSAvoidBVH construction time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by constructing a stochastic subset of the BVH that represents only a portion of the complete hierarchy. Instead of performing exhaustive traversal and intersection operations to build the complete BVH, the system builds a representative subset that captures the essential spatial relationships and intersection characteristics, thereby reducing construction time while maintaining sufficient rendering accuracy for real-time applications

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the parameter of BVH completeness from 100% to a stochastic representative subset. By adjusting the sampling density and subset size parameters, the system achieves a trade-off between construction speed and rendering quality, allowing fast construction for real-time graphics while maintaining acceptable accuracy through probability-based representation

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If exhaustive traversal and intersection operations are performed to construct BVH, then rendering accuracy is improved, but computational resource consumption increases

Engineering Contradiction:
Improverendering accuracyVSAvoidcomputational resource consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent reduces computational resource consumption by performing only partial traversal and intersection operations. Instead of processing every node and primitive in the complete BVH, the system samples a stochastic subset that provides sufficient spatial representation, thereby reducing CPU cycles, memory access, and energy consumption while maintaining acceptable rendering accuracy

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent creates a stochastic copy or representation of the complete BVH rather than processing the original exhaustive structure. This sampled subset BVH preserves the essential topological and spatial characteristics needed for ray tracing while consuming significantly fewer computational resources, effectively copying only the necessary information for real-time rendering

Inventive Principle:
Principle #26Copying

3Measurement precision

If complete BVH construction is performed, then ray tracing accuracy is improved, but real-time performance is reduced

Engineering Contradiction:
Improveray tracing accuracyVSAvoidreal-time performance
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies partial action by building only a stochastic subset of the BVH rather than the complete structure. This subset is constructed through random sampling of primitives and nodes, providing sufficient spatial representation for accurate ray-primitive intersection testing while dramatically reducing construction time to achieve real-time performance requirements

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent introduces dynamic adaptability in BVH construction by adjusting the sampling density and subset size based on scene complexity and performance requirements. The stochastic subset can be dynamically adjusted to balance between accuracy and speed, allowing the system to adapt to different rendering scenarios and maintain real-time performance across varying workloads

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4439472A1Apparatus and method for density-aware stochastic subsets for improved importance sampling
Publication Date: 2024.10.02 INTEL CORP
  • EP4439472A1 patent drawingFigure 1
  • EP4439472A1 patent drawingFigure 2A
  • EP4439472A1 patent drawingFigure 2B

AI summary

Apparatus and method for density-aware stochastic subsets for improved importance sampling. For example, one embodiment of an apparatus comprises: a sampling weight generator to determine a plurality of sampling weights associated with a corresponding plurality of input primitives, the sampling weight generator to determine each sampling weight based on a surface area or diagonal of a bounding box of the corresponding input primitive and a plurality of distance values corresponding to distances between the input primitive and a corresponding plurality of neighboring input primitives; a sampler to identify a representative subset of the input primitives based, at least in part, on the plurality of sampling weights; bounding volume hierarchy (BVH) builder hardware logic to construct an approximate BVH based on the representative subset of input primitives; hardware logic to insert input primitives not in the representative subset into leaves of the approximate BVH; and the BVH builder or a different BVH builder to construct a final BVH based on the primitives inserted into the leaves of the approximate BVH.