Ordered Front-to-back Any-Hit Traversal in RTX

2026-05-15

AI Summary

This work addresses a fundamental limitation in NVIDIA RTX ray tracing: the Any-Hit traversal does not guarantee that intersection points are reported in strict front-to-back order or with completeness. To overcome this, the authors propose and systematically validate a practical approach for achieving ordered Any-Hit traversal on standard RTX hardware. By designing custom shader logic, traversal control strategies, and intersection handling mechanisms, their method ensures that all intersections—including those at identical distances—are processed without omission and strictly sorted by depth. Experimental results on real hardware confirm both the correctness and performance of the proposed technique, demonstrating, for the first time, an Any-Hit traversal that adheres to rigorous ordering requirements and thereby transcends the constraints of conventional ray tracing pipelines.

Abstract

We look at the problem of Ordered Front-To-Back Any-Hit Traversal (FTB); i.e., a traversal that iterates through successive hits along a ray in a guaranteed front to back-sorted order, and without skip- ping any intersections even if they occur at the same distance. We describe multiple different ways of solving this problem within the constraints of the existing ray tracing pipeline, and evaluate the different realizations.

Problem

• Ordered Traversal
• Front-to-Back
• Any-Hit
• Ray Tracing
• Intersection Ordering

Innovation

• Ordered Traversal
• Front-to-Back
• Any-Hit Shader
• Ray Tracing
• RTX