ray_query

Vulkan Ray Query Implementation

Overview

This sample demonstrates the implementation of ray queries using the Vulkan ray tracing extension VK_KHR_ray_query, introduced in Vulkan 1.2.

Key Concepts

• GPU-based intersection testing between rays and geometry
• Efficient ray tracing for real-time rendering and physics simulations

Implementation Process

1. Acceleration Structure Creation

   • Construct bottom-level and top-level acceleration structures
   • Represents scene geometry for efficient traversal

2. Ray Query Dispatch

   • Specify ray origin and direction
   • Support for single or batch ray queries

3. Query Processing

   • GPU performs ray traversal and intersection testing
   • Utilizes acceleration structure for efficiency

4. Result Retrieval

   • Access intersection data (hit points, normals, distances)

Technical Advantages

• Selective intersection testing capabilities
• Performance optimization through test skipping (e.g., shadow tests)
• Enhanced flexibility compared to traditional ray tracing pipelines

Applications

• Real-time rendering
• Ray-based physics simulations
• Any scenario requiring accurate ray-geometry intersection testing

Performance Considerations

• Optimize acceleration structure updates for dynamic scenes
• Balance between query complexity and rendering performance