Reused Light Samples as Initial Candidates for Spatiotemporal Resampling

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Solution Overview

Problem

Existing sampling methods for spatiotemporal resampling in complex rendering tasks, such as in online gaming, often result in undersampling and inaccurate lighting due to factors like discontinuities, disocclusions, and challenging lighting conditions, leading to artifacts and unrealistic illumination.

Innovation Solution

Implementing a spatiotemporal resampling approach that reuses light samples with weight and effective sample count information, even when there is a discontinuous chain, by treating them as new initial candidates for importance resampling, and using a mixture probability distribution function to determine initial candidates for future frames.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If importance resampling is performed with a small number of samples reused over space and time, then the amount of data to be processed is reduced, but the accuracy of lighting estimation deteriorates due to undersampling

Engineering Contradiction:
Improveamount of data to be processedVSAvoidaccuracy of lighting estimation
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent performs preliminary actions by pre-computing and storing light samples with their weights and effective sample counts before they are needed for rendering. These pre-computed samples are then reused across multiple frames and spatial locations, eliminating the need to re-process the same data and reducing the overall data processing quantity while maintaining accuracy through the pre-stored representative samples.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameters of sample reuse by introducing weight values and effective sample count metrics that allow the same light samples to be reused multiple times with different importance weights. This enables the system to maintain high accuracy lighting estimation by weighting samples according to their contribution, while reducing the total number of samples needed to be processed.

Inventive Principle:
Principle #35Parameter changes

2Power

If sample reuse algorithms are used in budget-constrained environments, then computational resources are saved, but the quality of rendering deteriorates due to discontinuities and disocclusions

Engineering Contradiction:
Improvecomputational resourcesVSAvoidquality of rendering
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent implements feedback mechanisms where the rendering system continuously monitors and evaluates the quality of reused light samples. When discontinuities or disocclusions are detected that compromise rendering quality, the system adjusts the sampling strategy by selectively re-sampling affected regions while maintaining reuse in stable areas, thus preserving computational efficiency while ensuring rendering reliability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces dynamic adaptability to the sample reuse process by allowing the set of reused samples to change based on scene conditions. The system dynamically adjusts which samples are reused and which are re-computed based on factors like object motion, lighting changes, and occlusion events, maintaining rendering quality while optimizing computational resource usage.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If light samples are reused without weight or sample count information, then the complexity of sample management is reduced, but the accuracy of lighting calculation deteriorates

Engineering Contradiction:
Improvecomplexity of sample managementVSAvoidaccuracy of lighting calculation
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent makes light samples multi-functional by attaching weight values and effective sample count information to each sample, allowing the same sample data to serve multiple purposes: determining lighting accuracy, controlling reuse frequency, and adjusting importance across different spatial and temporal contexts. This universal enhancement to sample data enables accurate lighting calculation without requiring separate complex management systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS20250299434A1Initial candidates in spatiotemporal resampling
Publication Date: 2025.09.25 NVIDIA CORP
  • US20250299434A1 patent drawing
  • US20250299434A1 patent drawing
  • US20250299434A1 patent drawing

AI summary

Approaches in accordance with various illustrative embodiments provide for the selection and reuse of lighting sample data to generate high quality initial candidates, suitable for input to resampling techniques, that are better representative of the actual lighting of a scene for which an image, video frame, or other such representation is to be rendered. Instead of discarding an important light samples where weight or sample count may no longer be reliable, at least some of these samples can be provided as additional, unweighted candidates for use in importance sampling, in addition to those selected using a random (or semi-random) sampling process. Such an approach can help to ensure that important lights are considered when shading pixels for a scene, at least where such reuse makes sense due to changes in scene or location. Samples reused between frames can relate to various prior samples, such as samples that were determined to correspond to important, close, or bright lights.