Method for Reducing Network Bandwidth by Delaying Shadow Ray Generation

A computer readable storage medium containing a program which, when executed, performs an operation, comprising:

• issuing a ray into a three-dimensional scene;
• initiating on a first processing element:
• tracing the ray through a spatial index having nodes representing bounding volumes within the three-dimensional scene by taking branches to nodes defining bounding volumes intersected by the ray until a first leaf node is reached;
• after the leaf node is reached, sending information defining the ray and the first leaf node to a second processing element;
• receiving information defining a first set of secondary rays and information defining a ray-primitive intersection point from the second processing element;
• and generating a second set of secondary rays based on at least the information defining the ray-primitive intersection point.

A system, comprising:

• a first processing element;
• a second processing element;
• a memory device comprising a spatial index having nodes defining bounding volumes of a three-dimensional scene;
• a communication network coupled to the first processing element and the second processing element;
• wherein the first processing element is configured to traverse a ray through the spatial index by taking branches to nodes defining bounding volumes intersected by the ray until a leaf node is reached, and send the information defining the ray and the leaf node to the second processing element via the communication network;
• wherein the second processing element is configured to determine if the ray intersects a primitive contained within a bounding volume defined by the leaf node;
• generate a first set of secondary rays;
• send information defining the first set of secondary rays to the first processing element;
• and send information defining a ray-primitive intersection point to the first processing element;
• and
• wherein the first processing element is further configured to generate a second set of secondary rays based on at least the ray-primitive intersection point.