BVH Sibling Discarding for Faster Ray Tracing Traversal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ray tracing operations that utilize bounding volume hierarchies (BVH) trees consume excessive system resources and time due to unnecessary traversal of nodes, particularly in wider BVH structures, which limits the quality of generated images.
Innovation Solution
Implementing discard values to omit traversal of nodes in the BVH stack based on overlap data, either pre-computed or determined during traversal, to reduce the number of nodes processed, using techniques applicable in various processing circuits including GPUs, GPGPUs, and AI processors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional approaches traverse all nodes in the BVH tree structure, then complete scene coverage is achieved, but system resource consumption and traversal time increase significantly
Solution Approach 1:
The patent extracts and removes unnecessary nodes from the BVH traversal process by implementing discard values. When a node is marked for discarding, the traversal algorithm skips that node and its entire subtree, effectively taking out non-essential processing from the ray tracing pipeline while maintaining coverage of relevant scene elements.
Solution Approach 2:
The patent changes the traversal parameter by introducing discard values that modify the traversal behavior. Instead of uniformly processing all nodes, the system dynamically adjusts traversal based on discard markers, allowing selective omission of nodes that don't contribute to the final image quality, thus reducing traversal time without compromising essential scene coverage.
2Manufacturing precision
If wider BVH structures are used to improve rendering quality, then image fidelity increases, but the number of nodes to traverse increases, consuming more resources and time
Solution Approach 1:
The patent applies the extraction principle by removing redundant nodes from wider BVH structures through discard values. Even though wider BVH trees provide better image fidelity by capturing more scene detail, the discard mechanism extracts and eliminates nodes that would not contribute to the final rendered image, thereby restoring productivity despite the increased structural complexity.
Solution Approach 2:
The patent implements partial action by traversing only the necessary portion of the BVH tree rather than all nodes. Discard values enable the system to perform partial traversal, processing only those nodes that contribute to image fidelity while skipping excessive nodes that would otherwise be processed, thus balancing quality and efficiency.
3Measurement precision
If more nodes are included in the BVH tree to represent complex scenes, then scene representation accuracy improves, but traversal resource consumption increases
Solution Approach 1:
The patent uses the extraction principle to remove unnecessary computational work from BVH traversal by implementing discard values. Complex scenes require more nodes for accurate representation, but the discard mechanism extracts and eliminates nodes that would not be visited during actual ray tracing, reducing energy consumption while preserving scene representation accuracy for visible elements.
Solution Approach 2:
The patent changes the traversal parameter space by introducing discard values that dynamically control node processing. This allows the system to maintain high scene representation accuracy by preserving all necessary nodes in the BVH structure, while simultaneously reducing energy consumption by marking and skipping nodes that would not contribute to the final image, effectively decoupling structural completeness from processing requirements.
Data Source
AI summary
A processing circuit is configured to generate frames based on ray tracing context data stored by a bounding volume hierarchy (BVH) structure. Generating the stream of frames includes traversing the BVH structure, which includes a plurality of nodes. As part of traversing the BVH structure, in response to detecting that a ray intersects with a first bounding volume (BV) or primitive corresponding to a first node of the BVH structure, a discard value is checked, where the discard value is generated based on overlaps between the first BV or primitive and at least one BV or primitive corresponding to at least one sibling node of the BVH structure. In response to the discard value indicating that the sibling node is to be discarded, traversal of the sibling node is omitted. In response to the discard value indicating that the sibling node is to be traversed, the sibling node is traversed.