Apple Inc.

Justin A Hensley

Christopher A Burns

Jonathan M Redshaw

Ali Rabbani Rankouhi

Terence M Potter

Ralph Clay Taylor

Luca O Iuliano

Karl D Mann

Guy Cote

Jim Chen Chou

Avi Bar-Zeev

Hao Pan

Sheng Zhang

Arthur Yasheng Zhang

Geoffrey Grant Stahl

Yoong Chert Foo

Gurjeet S Saund

Ray Ling Chang

Timothy Robert Oriol

Tobias Eble

Richard Warren Schreyer

Ling Su

Aaftab A Munshi

Tyson J Bergland

Karthik Ramani

Frank W Liljeros

Stephan Lachowsky

Randall R Rauwendaal

Davoud A Jamshidi

Robert D Kenney

Techniques are disclosed relating to dynamically allocating and mapping private memory for requesting circuitry. Disclosed circuitry may receive a private address and translate the private address to a virtual address (which an MMU may then translate to physical address to actually access a storage element). In some embodiments, private memory allocation circuitry is configured to generate page table information and map private memory pages for requests if the page table information is not already setup. In various embodiments, this may advantageously allow dynamic private memory allocation, e.g., to efficiently allocate memory for graphics shaders with different types of workloads. Disclosed caching techniques for page table information may improve performance relative to traditional techniques. Further, disclosed embodiments may facilitate memory consolidation across a device such as a graphics processor.

On-demand memory allocation

Disclosed techniques relate to acceleration data structure for ray intersection testing. In some embodiments, storage circuitry stores node data for a spatially organized acceleration data structure, including to store the following node information for a given node: origin coordinates for the node and, for a given child node of multiple child nodes, child information that includes: quantized bounding region information for a bounding region corresponding to the child node, where the quantized bounding region information encodes bounding region coordinates as offsets relative to the origin coordinates. Traversal circuitry may traverse multiple nodes of the data structure and determine whether a ray intersects a bounding region indicated by given a node of the data structure based on the node information. Disclosed techniques may provide substantial improvements to performance, data size, and power consumption.

Node encoding for spatially-organized ray tracing acceleration data structure

A mixed reality system that includes a device and a base station that communicate via a wireless connection The device may include sensors that collect information about the user's environment and about the user. The information collected by the sensors may be transmitted to the base station via the wireless connection. The base station renders frames or slices based at least in part on the sensor information received from the device, encodes the frames or slices, and transmits the compressed frames or slices to the device for decoding and display. The base station may provide more computing power than conventional stand-alone systems, and the wireless connection does not tether the device to the base station as in conventional tethered systems. The system may implement methods and apparatus to maintain a target frame rate through the wireless link and to minimize latency in frame rendering, transmittal, and display.

Video pipeline

Techniques are disclosed relating to compression of pixel data using different quantization for different regions of a block of pixels being compressed. In some embodiments, compression circuitry is configured to determine, for multiple components included in pixels of the block of pixels being compressed, respective smallest and greatest component values in respective regions of the block of pixels. The compression circuitry may determine, based on the determined smallest and greatest component values, to use a first number of bits to represent delta values relative to a base value for a first component in a first region and a second, different number of bits to represent delta values relative to a base value for a second component in the first region. The compression circuitry may then quantize delta values for the first and second components of pixels in the first region of the block of pixels using the determined first and second numbers of bits. In some embodiments, the compression circuitry determines whether to provide cross-component bit sharing within a region.

Lossy compression techniques

Disclosed techniques relate to forming single-instruction multiple-data (SIMD) groups during ray intersection traversal. In particular, ray intersection circuitry may include dedicated circuitry configured to traverse an acceleration data structure, but may dynamically form a SIMD group to transform ray coordinates when traversing from one level of the data structure to another. This may allow shader processors to execute the SIMD group to perform the transformation. Disclosed techniques may facilitate instancing of graphics models within the acceleration data structure.

SIMD group formation techniques during ray intersection traversal

Techniques are disclosed relating to ray intersection in the context of motion blur. In some embodiments, a graphics processor includes time-oblivious ray intersect circuitry configured to receive coordinates for a ray and traverse a bounding volume hierarchy (BVH) data structure based on the coordinates to determine whether the ray intersects with one or more bounding regions of a graphics space. In some embodiments, in response to reaching a temporal branch element of the BVH data structure, the ray intersect circuitry initiates a shader program that determines a sub-tree of the BVH data structure for further traversal by the ray intersection circuitry, where the sub-tree corresponds to a portion of a motion-blur interval in which the ray falls. This may provide accurate ray tracing for motion blur while reducing area and power consumption of intersect circuitry, relative to time-aware implementations.

Temporal split techniques for motion blur and ray intersection

Disclosed techniques relate to memory space management for graphics processing. In some embodiments, first and second graphics cores are configured to execute instructions for multiple threadgroups. In some embodiments, the threads groups include a first threadgroup with multiple single-instruction multiple-data (SIMD) groups configured to execute a first shader program and a second threadgroup with multiple SIMD groups configured to execute a second, different shader program. Control circuitry may be configured to provide access to data stored in memory circuitry according to a shader memory space. The shader memory space may be accessible to threadgroups executed by the first graphics shader core, including the first and second threadgroups, but is not accessible to threadgroups executed by the second graphics shader core. Disclosed techniques may reduce latency, increase bandwidth available to the shader, reduce coherency cost, or any combination thereof.

Graphics memory space for shader core

Disclosed techniques relate to primitive testing associated with ray intersection processing for ray tracing. In some embodiments, shader circuitry executes a first SIMD group that includes a ray intersect instruction for a set of rays. Ray intersect circuitry traverses, in response to the ray intersect instruction, multiple nodes in a spatially organized acceleration data structure (ADS). In response to reaching a node of the ADS that indicates one or more primitives, the apparatus forms a second SIMD group that executes one or more instructions to determine whether a set of rays that have reached the node intersect the one or more primitives. The shader circuitry may execute the first SIMD group to shade one or more primitives that are indicated as intersected based on results of execution of the second SIMD group. Thus, disclosed techniques may use both dedicated ray intersect circuitry and dynamically formed SIMD groups executed by shader processors to detect ray intersection.

SIMD group formation techniques for primitive testing associated with ray intersect traversal

Disclosed techniques relate to grouping rays during traversal of a spatially-organized acceleration data structure (e.g., a bounding volume hierarchy) for ray intersection processing. The grouping may provide temporal locality for accesses to bounding region data. In some embodiments, ray intersect circuitry is configured to group rays based on the node of the data structure that they target next. The ray intersect circuitry may select one or more groups of rays for issuance each clock cycle, e.g., to bounding region test circuitry.

Grouping techniques for ray intersection traversal

Disclosed techniques relate to ray intersection processing for ray tracing. In some embodiments, ray intersection circuitry traverses a spatially organized acceleration data structure and includes bounding region circuitry configured to test, in parallel, whether a ray intersects multiple different bounding regions indicated by a node of the data structure. Shader circuitry may execute a ray intersect instruction to invoke traversal by the ray intersect circuitry and the traversal may generate intersection results. The shader circuitry may shade intersected primitives based on the intersection results. Disclosed techniques that share processing between intersection circuitry and shader processors may improve performance, reduce power consumption, or both, relative to traditional techniques.

Ray intersect circuitry with parallel ray testing

Disclosed techniques relate to an acceleration data structure for ray intersection with a many-to-many mapping between bounding regions and primitives. In some embodiments, one or more graphics processors access data for multiple graphics primitives in a graphics scene and generate a spatially organized data structure. Some nodes of the data structure indicate graphics primitives and some nodes indicate coordinates of bounding regions in the graphics scene. In some embodiments, the spatially organized data structure includes a node with a bounding region for which multiple primitives are indicated as children and also includes a primitive for which multiple bounding regions are indicated as parents. Disclosed techniques may generate bounding regions that closely fit primitives, which may reduce primitive testing for ray tracing. This in turn may increase performance or reduce power consumption relative to traditional techniques.

Ray intersection data structure with many-to-many mapping between bounding regions and primitives

Techniques are disclosed relating to rendering graphics objects. In some embodiments, a graphics unit is configured to transform graphics objects from a virtual space into a second space according to different transformation parameters for different portions of the second space. This may result in sampling different portions of the virtual space at different sample rates, which may reduce the number of samples required in various stages of the rendering process. In the disclosed techniques, transformation may occur prior to rasterization and shading, which may further reduce computation and power consumption in a graphics unit, improve image quality as displayed to a user, and/or reduce bandwidth usage or latency of video content on a network. In some embodiments, a transformed image may be viewed through a distortion-compensating lens or resampled prior to display.

Growing community of inventors

Mountain View, CA, United States of America

Justin A Hensley