Ray Tracing Motion Blur with Spacetime Bounding Volume Interpolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Combining motion blur with ray tracing in graphics processing is resource-intensive and power-consuming due to the need for extensive processor tests on moving primitives, leading to performance degradation.
Innovation Solution
Implement spacetime interpolation circuitry to generate interpolated bounding boxes for ray tracing, using quantized interval values to improve performance and reduce power consumption by optimizing ray-primitive intersection tests.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ray tracing with motion blur is implemented using traditional bounding volume hierarchies, then rendering quality is improved, but processor resources and power consumption increase significantly
Solution Approach 1:
The patent introduces a temporal dimension to the bounding volume hierarchy by storing multiple bounding volumes at different time steps within each node. This spacetime BVH structure allows the system to handle motion blur by pre-computing bounding volumes at discrete time points, transforming the traditional 3D spatial problem into a 4D spacetime problem that can be efficiently queried during ray tracing.
Solution Approach 2:
The system pre-computes and stores bounding volumes at multiple time steps during the setup phase, before actual ray tracing occurs. This preliminary action allows the ray tracer to simply query pre-computed bounding volumes during rendering, avoiding the need to perform complex motion blur calculations in real-time and significantly reducing processor resource consumption.
2Reliability
If bounding volumes are expanded to cover all possible positions during motion blur interval, then all moving primitives are captured, but the number of ray-primitive intersection tests increases
Solution Approach 1:
The patent segments the motion blur interval into multiple discrete time steps, storing separate bounding volumes for each time step within BVH nodes. This segmentation allows the system to represent the motion trajectory of primitives accurately while enabling efficient query processing, as rays only need to test against bounding volumes relevant to their specific time of interaction rather than testing all possible positions.
Solution Approach 2:
The system dynamically selects which bounding volumes to test based on the ray's time parameter. Instead of statically testing all bounding volumes in the hierarchy, the system adapts its search based on the temporal information, only performing intersection tests against bounding volumes that are active at the ray's specific time, thereby reducing the number of tests while maintaining comprehensive coverage.
Data Source
AI summary
Techniques are disclosed relating to ray tracing and motion blur in graphics processors. In some embodiments, ray intersection accelerator circuitry is configured to perform traversal operations for an acceleration data structure (ADS) that includes hierarchical bounding volumes, where the ADS includes a first node that specifies: first coordinates of a bounding volume at a first motion blur time and second coordinates of the bounding volume at a second motion blur time. The Ray accelerator may determine a ray time interval representation indicating upper and lower bounds that represent error bounds for a quantized ray time value of a ray. Interpolation circuitry may operate on the first coordinates, the second coordinates, and the ray time interval representation to generate interpolated coordinates for the bounding volume. Box test circuitry may determine whether the ray intersected the bounding volume based on the interpolated coordinates and coordinates of the ray.