Nvidia Corporation

Peter Nelson

John Matthew Burgess

William P Newhall, Jr

Greg Muthler

Samuli Matias Laine

Timo Oskari Aila

Tero Tapani Karras

Olivier Giroux

Ronald Charles Babich, Jr

Robert Ohannessian

Gary M Tarolli

James Robertson

Ajay Sudarshan Tirumala

Ian Kwong

Rishkul Kulkarni

Konstantinos Kyriakopoulos

Ankita Upreti

Divya Shanmughan

In a ray tracer, to prevent any long-running query from hanging the graphics processing unit, a traversal coprocessor provides a preemption mechanism that will allow rays to stop processing or time out early. The example non-limiting implementations described herein provide such a preemption mechanism, including a forward progress guarantee, and additional programmable timeout options that can be time or cycle based. Those programmable options provide a means for quality of service timing guarantees for applications such as virtual reality (VR) that have strict timing requirements.

Method for forward progress and programmable timeouts of tree traversal mechanisms in hardware

Various embodiments include a parallel processing computer system that enables parallel instances of a program to synchronize at disparate addresses in memory. When the parallel program instances need to exchange data, the program instances synchronize based on a mask that identifies the program instances that are synchronizing. As each program instance reaches the point of synchronization, the program instance blocks and waits for all other program instances to reach the point of synchronization. When all program instances have reached the point of synchronization, at least one program instance executes a synchronous operation to exchange data. The program instances then continue execution at respective and disparate return addresses.

Techniques for efficiently synchronizing multiple program threads

A hardware-based traversal coprocessor provides acceleration of tree traversal operations searching for intersections between primitives represented in a tree data structure and a ray. The primitives may include triangles used in generating a virtual scene. The hardware-based traversal coprocessor is configured to properly handle numerically challenging computations at or near edges and/or vertices of primitives and/or ensure that a single intersection is reported when a ray intersects a surface formed by primitives at or near edges and/or vertices of the primitives.

Watertight ray triangle intersection

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Peter Nelson