Vectorized Node Reordering for Ray Tracing Occlusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ray tracing algorithms face inefficiencies in calculating occlusion of a point along a line in a scene with multiple geometrical objects, particularly when using spatial data structures like Bounding Volume Hierarchies, as they require complex node ordering and traversal operations that are not optimized for wide vector instructions.
Innovation Solution
The method involves obtaining ordering information for a tree structure, selecting a predetermined ordering parameter template based on this information, and using a single processor operation with a vector processing instruction set to copy and reorder nodes within a memory region, enabling efficient traversal and occlusion determination by quantizing directions and using vector permute and compaction operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex node ordering and traversal operations are used in ray tracing algorithms, then occlusion calculation accuracy is improved, but processing time and computational complexity increase
Solution Approach 1:
The patent pre-calculates and stores ordering parameters for all possible ray direction quantizations before actual ray tracing execution. This preliminary preparation allows the traversal algorithm to directly retrieve and apply pre-determined node ordering sequences during occlusion calculation, eliminating the need for complex real-time sorting operations while maintaining accurate occlusion detection
Solution Approach 2:
The patent implements dynamic node ordering by storing multiple predetermined ordering parameter templates corresponding to different ray direction quantizations. During traversal, the algorithm dynamically selects and applies the appropriate ordering parameters based on the actual ray direction, enabling adaptive optimization of node visitation sequences without sacrificing occlusion calculation accuracy
2Productivity
If traditional traversal operations are used without vector optimization, then algorithm compatibility is maintained, but processing speed decreases
Solution Approach 1:
The patent replaces traditional scalar-based node traversal operations with vectorized processing using AVX-512 instruction set. By representing node ordering parameters and traversal sequences as vectors, the algorithm leverages hardware-level parallel processing capabilities to simultaneously process multiple nodes, achieving significant speedup while managing complexity through standardized vector operations
3Productivity
If node reordering is performed during traversal, then traversal efficiency is improved, but memory access patterns become more complex
Solution Approach 1:
The patent pre-computes and stores optimal node ordering sequences in memory before traversal begins. These predetermined ordering parameters are organized in a lookup structure that maps ray direction quantizations to corresponding node visitation sequences. During traversal, the algorithm simply retrieves and follows these pre-established sequences, improving efficiency while avoiding complex real-time reordering logic
Solution Approach 2:
The patent transforms the node reordering problem from a temporal sequence operation into a spatial memory organization problem. By storing multiple predetermined ordering parameter templates in memory arranged according to ray direction quantizations, the algorithm converts dynamic reordering requirements into static memory layout optimizations, simplifying the traversal logic while maintaining efficiency
Data Source
AI summary
Examples relate to methods, a computer program and an apparatus for an ordered traversal of a subset of nodes of a tree structure and/or for determining an occlusion of a point along a ray in a raytracing scene. The method for the ordered traversal of the subset of nodes of the tree structure comprises obtaining ordering information indicating a desired order of the ordered traversal of the tree structure. The method further comprises selecting a predetermined ordering parameter template from a plurality of predetermined ordering parameter templates based on the ordering information. The method further comprises copying the subset of nodes of the tree structure from a first memory region to a second memory region using a single processor operation of a vector processing processor instruction set such that the subset of nodes of the tree structure is stored within the second memory region in the desired order. The selected predetermined ordering parameter template is used as a parameter for the single processor operation.