Systems and methods for a ray tracing shader api

A system for tracing rays in a scene, comprising:

• a ray intersection testing resource operable to test rays for intersection in the scene;
• a buffer for accumulating shading results;
• and
• computer readable media storing code for implementing a programming interface, the programming interface comprising an emit ray call, for use by shaders to specify rays to be intersection tested, and a contribute call for interfacing shaders with the buffer by accepting, during shader execution, data representative of a result to be contributed directly to one or more locations in the buffer.

A computer readable medium storing computer readable instructions for execution on a computer to implement a shading interface method, comprising:

• accepting data from a first shader comprising an origin and a direction for a ray to be intersection tested in a 3-D scene;
• accepting, from the first shader, additional data to associate with the ray;
• and
• causing the additional data to be communicated to a second shader that is identified based on results of intersection testing the ray.