Ray Tracing Clipping for Rendering Performance

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Solution Overview

Problem

Current ray tracing methods are computationally intensive, making real-time high-quality and high-resolution rendering of 3-D scenes challenging, as they require substantial computational resources and time, especially when dealing with complex scenes and light sources.

Innovation Solution

The method involves instantiating rays with clipping information to limit intersection testing to a maximum distance from the origin, allowing for efficient traversal of acceleration structures by only testing geometric objects within this distance, thereby reducing unnecessary computations and accelerating the rendering process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If ray tracing is used to render photo-realistic images with realistic shadow and lighting effects, then image quality and realism are improved, but computational time and resource requirements increase substantially

Engineering Contradiction:
Improveimage qualityVSAvoidcomputational time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention segments the scene into multiple bounding volumes organized in a hierarchy, allowing the ray tracing algorithm to process only relevant portions of the scene. By dividing the scene into manageable spatial segments, the system avoids computing intersections with all primitives in the entire scene, thus reducing computational time while maintaining image quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies partial action by testing rays against only those bounding volumes and primitives that are potentially relevant to the ray's path, rather than testing against all primitives in the scene. The clipping distance parameter further limits the action to only the necessary portion of the scene, avoiding excessive computations while preserving rendering quality.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If intersection testing is performed against all scene primitives to ensure accuracy, then rendering precision is improved, but computational overhead increases

Engineering Contradiction:
Improveintersection testing accuracyVSAvoidcomputational overhead
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention applies local quality by creating a hierarchy of bounding volumes where each node in the hierarchy represents a local region of the scene. The algorithm traverses this hierarchy and performs detailed intersection testing only in local regions that are relevant to the ray's path, determined by the clipping distance. This localized approach maintains precision where needed while reducing overall computational overhead.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention performs preliminary action by organizing primitives into a pre-computed bounding volume hierarchy before ray tracing begins. This hierarchical structure is prepared in advance, allowing the rendering algorithm to quickly navigate to relevant regions without performing exhaustive searches during the actual ray tracing process, thus reducing computational overhead while maintaining accuracy.

Inventive Principle:
Principle #10Preliminary action

3Speed

If the scene is divided into multiple bounding volumes for faster traversal, then traversal speed is improved, but data structure complexity increases

Engineering Contradiction:
Improvetraversal speedVSAvoiddata structure complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The invention implements the nested doll principle by creating a hierarchy of bounding volumes where smaller bounding volumes are nested within larger ones, forming a tree-like structure. This nested organization allows the traversal algorithm to quickly eliminate large portions of the scene by testing against outer bounding volumes first, then progressively narrowing down to inner volumes, thus improving traversal speed while managing complexity through hierarchical organization.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP2335224B1Ray tracing using ray-specific clipping
Publication Date: 2017.07.12 IMAGINATION TECH LTD
  • EP2335224B1 patent drawingFigure 1~3B
  • EP2335224B1 patent drawingFigure 4~6
  • EP2335224B1 patent drawingFigure 7

AI summary

Systems, methods, and computer readable media embodying such methods provide for allowing specification of per-ray clipping information that defines a sub-portion of a 3-D scene in which the ray should be traced. The clipping information can be specified as a clip distance from a ray origin, as an end value of a parametric ray definition, or alternatively the clipping information can be built into a definition of the ray to be traced. The clipping information can be used to check whether portions of an acceleration structure need to be traversed, as well as whether primitives should be tested for intersection. Other aspects include specifying a default object that can be returned as intersected when no primitive was intersected within the sub-portion defined for testing. Further aspects include allowing provision of flags interpretable by an intersection testing resource that control what the intersection testing resource does, and/or what information it reports after conclusion of testing of a ray.