Sony patents method for “significant improvement of ray tracing speed”

Whereas online game consoles have lastly reached the age of ray tracing, performing these graphical calculations in actual time can nonetheless be robust on consumer-level {hardware}. A PS5 sport like Gran Turismo 7, as an example, can solely deal with ray-traced visuals in replays due to the processing necessities.

With a newly filed patent, although, Sony engineer Mark Cerny lays out a way that might considerably pace up the ray-tracing course of by offloading sure calculations from the GPU to specifically designed ray-tracing unit (RTU) {hardware}. The outlines of the brand new ray-tracing course of are specified by a patent software titled “System and methodology for accelerated ray tracing with asynchronous operation and ray transformation.” The appliance was revealed within the European Union final week after being filed final August.

In Cerny’s methodology, the RTU {hardware} is specifically designed to effectively traverse so-called acceleration buildings in a 3D atmosphere, going by means of a stack of bounding volumes to determine factors the place a digital gentle ray intersects with an object. These intersections are then despatched to a shader program working on the GPU, which determines whether or not the thing is opaque (a “hit” for the ray-tracing algorithm) or clear (i.e., the intersection might be ignored).

Within the case of successful, the GPU can then ship that data again to the RTU, which may “shorten the ray, as there isn’t any level testing previous the placement of the intersection of the ray with [the opaque object].” That saves processing time that may be wasted calculating additional “hits” for objects which can be occluded by a more in-depth object.

Crucially, these RTU features “might be asynchronous with respect to the shader program.” Meaning the GPU can carry out different features because it waits for the RTU to ship again any intersections it finds between gentle rays and in-game objects.

Dealing with these fundamentals features within the RTU (which “could embody {hardware} circuitry” specifically designed for this traversal) “could lead to a major enchancment of ray tracing pace,” the patent says, “because the shader program is simply performing hit testing. It isn’t performing acceleration construction traversal or managing the corresponding stack.”

When will we see outcomes?

The publication of a patent like this from Sony suggests the corporate has its eye on bettering ray-tracing efficiency on the PlayStation 5. However it’s unclear how the tactic described on this patent would combine with the console’s present ray-tracing pipeline, which is constructed on AMD’s RDNA2 structure.

That AMD pipeline already makes use of ray accelerators to assist calculate intersections. The pipeline, nonetheless, leaves the expensive acceleration construction traversal (i.e., shifting by means of a sequence of “bounding volumes” in 3D house) to the GPU shader. That is in distinction to Nvidia’s graphics playing cards, which basically deal with your complete ray-tracing pipeline on specialised cores.

As such, the PS5’s ray-tracing cores will not be designed to effectively deal with the traversal as described on this patent. However future redesigns of the PS5 processor (a la the PS4 Professional) or future Sony {hardware} altogether might make use of a brand new {hardware} structure designed to benefit from this patent-pending methodology.

Or possibly not. Firms typically file patents for options that by no means develop into client merchandise for one cause or one other. On this case, the tactic is buried so deep within the {hardware} that common customers won’t even discover if/when it is carried out. Nonetheless, a glimpse at how an organization like Sony is seeking to enhance the effectivity of its graphical pipeline is attention-grabbing.

Andrew Cunningham contributed to this report.

Itemizing picture by CD Projekt Crimson