1. [Publications](/index.php/publications)
2. What is a Ray?

 # What is a Ray?

  ![Publication image](/sites/default/files/styles/wide/public/default_images/default.jpeg?itok=TfIobf92 "Publication image")

 We define a ray, show how to use ray intervals, and demonstrate how to specify a ray using DirectX Raytracing (DXR)

 ## Authors

Peter Shirley (NVIDIA)

Ingo Wald (NVIDIA)

[Tomas Akenine-Möller](/index.php/person/tomas-akenine-moller)

Eric Haines (NVIDIA)

 ## Publication Date

Friday, March 1, 2019

 ## Published in

[Ray Tracing Gems](http://www.realtimerendering.com/raytracinggems/)

 ## Research Area

[Real-Time Rendering](/index.php/research-area/real-time-rendering)