Abstract: Some implementations provide systems, devices, and methods for implementing a cache replacement policy. A memory request is issued for attribute information associated with a node in an acceleration data structure. The attribute information associated with the node is inserted into a cache entry of the cache and an age associated with the cache entry is set to a value based on the attribute information, in response to the memory request causing a cache miss.

Abstract: Techniques for performing ray tracing operations are provided. The techniques include receiving a request to determine whether a ray intersects any primitive of a set of primitives, evaluating the ray against non-leaf nodes of a bounding volume hierarchy to determine whether to eliminate portions of the bounding volume hierarchy from consideration, evaluating the ray against at least one early-termination node not eliminated from consideration, and determining whether to terminate traversal of the bounding volume hierarchy early and to identify that the ray hits a primitive, based on the result of the evaluation of the ray against the at least one early-termination node.

Abstract: A server offloads graphics effects processing to a client device with graphics processing resources by determining a modification to a graphics effects operation, generating a portion of a rendered video stream using the modification to the graphics effects operation, and providing an encoded representation of the portion of the rendered video stream to the client device, along with metadata representing the modification implemented. The client device decodes the encoded representation to recover the portion of the rendered video stream and selectively performs a graphics effects operation on the recovered portion to at least partially revert the resulting graphics effects for the portion to the intended effects without the modification implemented by the server.

Abstract: An engagement analytics engine of a computing device analyzes one or more of scene representations, player inputs, or player meta information and generates corresponding engagement data indicative of a level of engagement corresponding to the represented scene. The engagement analytics engine generates encoding parameters based on the engagement data to cause scenes or regions within scenes to be encoded with a level of quality based on the indicated level of engagement. In some examples, the engagement analytics engine generates rendering parameters based on the engagement data to cause scenes to be rendered with a frame rate or quality parameters based on the indicated level of engagement. In some examples, the engagement analytics engine causes a load balancer to shift workloads associated with one or more scenes to higher or lower performance servers based on the engagement data.

Abstract: Systems, apparatuses, and methods for implementing a single-stream foveal display transport are disclosed. A system includes a transmitter sending an image over a display transport as a sequence of equi-sized rectangles to a receiver coupled to a display. The receiver then scales up the rectangles with different scale factors to cover display areas of different sizes. The pixel density within a rectangular region is uniform and scaling factors can take on integer or non-integer values. The rectilinear grid arrangement of the image results in simplified scaling operations for the display. In another scenario, the image is transmitted as a set of horizontal bands of equal size. Within each band, the same horizontal amount of transmitted pixels are redistributed across multiple rectangular regions of varied scales. The display stream includes embedded information and the horizontal and/or vertical distribution and scaling of rectangular regions, which can be adjusted for each transmitted image.

Abstract: Systems, apparatuses, and methods for using a multi-stream foveal display transport layer are disclosed. A virtual reality (VR) system includes a transmitter sending a plurality of streams over a display transport layer to a receiver coupled to a display. Each stream corresponds to a different image to be blended together by the receiver. The images include at least a foveal region image corresponding to a gaze direction of the eye and a background image which is a lower-resolution image with a wider field of view than the foveal region image. The phase timing of the foveal region stream being sent over the transport layer is adjusted with respect to the background stream to correspond to the location of the foveal region within the overall image. This helps to reduce the amount of buffering needed at the receiver for blending the images together to create a final image to be driven to the display.

Abstract: A technique for generating encoded video in a client-server system is provided. According to the technique, a server determines that reprojection analysis should occur. The server generates reprojection metadata based on suitability of video content to reprojection. The server generates encoded video based on the reprojection metadata, and transmits the encoded video to a client for display. The client reprojects video content as directed by the server.

Abstract: Systems, apparatuses, and methods for implementing a single-stream foveal display transport are disclosed. A system includes a transmitter sending an image over a display transport as a sequence of equi-sized rectangles to a receiver coupled to a display. The receiver then scales up the rectangles with different scale factors to cover display areas of different sizes. The pixel density within a rectangular region is uniform and scaling factors can take on integer or non-integer values. The rectilinear grid arrangement of the image results in simplified scaling operations for the display. In another scenario, the image is transmitted as a set of horizontal bands of equal size. Within each band, the same horizontal amount of transmitted pixels are redistributed across multiple rectangular regions of varied scales. The display stream includes embedded information and the horizontal and/or vertical distribution and scaling of rectangular regions, which can be adjusted for each transmitted image.

Abstract: Methods are provided for creating objects in a way that permits an API client to explicitly participate in memory management for an object created using the API. Methods for managing data object memory include requesting memory requirements for an object using an API and expressly allocating a memory location for the object based on the memory requirements. Methods are also provided for cloning objects such that a state of the object remains unchanged from the original object to the cloned object or can be explicitly specified.

Abstract: Shader resources may be specified for input to a shader using a hierarchical data structure which may be referred to as a descriptor set. The descriptor set may be bound to a bind point of the shader and may contain slots with pointers to memory containing shader resources. The shader may reference a particular slot of the descriptor set using an offset, and may change shader resources by referencing a different slot of the descriptor set or by binding or rebinding a new descriptor set. A graphics pipeline may be specified by creating a pipeline object which specifies a shader and a rendering context object, and linking the pipeline object. Part or all of the pipeline may be validated, cross-validated, or optimized during linking.

Abstract: Methods are provided for creating objects in a way that permits an API client to explicitly participate in memory management for an object created using the API. Methods for managing data object memory include requesting memory requirements for an object using an API and expressly allocating a memory location for the object based on the memory requirements. Methods are also provided for cloning objects such that a state of the object remains unchanged from the original object to the cloned object or can be explicitly specified.

Abstract: Systems, methods and apparatuses of processing data of a VR system are disclosed that comprise receiving tracking information which includes at least one of user position information and eye gaze point information. One or more processors may be used to predict, based on the user tracking information, a user viewpoint of a next frame of a sequence of frames of video data to be displayed. Using the prediction, a portion of the next frame of video data to be displayed is rendered at an estimated location in the next frame. A corresponding matching portion in a previously encoded frame is determined based on the estimated location of the portion in the next frame and the portion of the next frame of video data is encoded.

Abstract: In a processing system including a plurality of graphics processing units (GPUs), the GPUs transfer compressed graphics streams composed of blocks of graphics data to one another. Some blocks of a compressed graphics stream, or parts thereof, may contain both compressed graphics data and meaningless data (referred to as data structure padding, or padding) that is used to align the graphics data, and some blocks may contain only padding. Before transferring a compressed graphics resource from one GPU to another GPU, the sending GPU compacts the compressed graphics resource by filtering out padding from the compressed graphics stream prepared for the transfer.

Abstract: Shader resources may be specified for input to a shader using a hierarchical data structure which may be referred to as a descriptor set. The descriptor set may be bound to a bind point of the shader and may contain slots with pointers to memory containing shader resources. The shader may reference a particular slot of the descriptor set using an offset, and may change shader resources by referencing a different slot of the descriptor set or by binding or rebinding a new descriptor set. A graphics pipeline may be specified by creating a pipeline object which specifies a shader and a rendering context object, and linking the pipeline object. Part or all of the pipeline may be validated, cross-validated, or optimized during linking.

Abstract: A processing system selectively renders pixels or blocks of pixels of an image and leaves some pixels or blocks of pixels unrendered to conserve resources. The processing system generates a motion vector field to identify regions of an image having moving areas. The processing system uses a rendering processor to identify as regions of interest those units having little to no motion, based on the motion vector field, and a large amount of edge activity, and to minimize the probability of unrendered pixels, or “holes”, in these regions. To avoid noticeable patterns, the rendering processor applies a probability map to determine the possible locations of holes, assigning to each unit a probability indicating the percentage of pixels within the unit that will be holes, and assigning a lower probability to units identified as regions of interest.

Abstract: Various virtual reality computing systems and methods are disclosed. In one aspect, a method of delivering video frame data to multiple VR displays is provided. The method includes generating content for multiple VR displays and sensing for competing needs for resources with real time requirements of the multiple VR displays. If competing needs for resources with real time requirements are sensed, a selected refresh offset for refreshes of the multiple VR displays is determined to avoid conflict between the competing needs for resources of the multiple VR displays. The selected refresh offset is imposed and the content is delivered to the multiple VR displays.

Abstract: Shader resources may be specified for input to a shader using a hierarchical data structure which may be referred to as a descriptor set. The descriptor set may be bound to a bind point of the shader and may contain slots with pointers to memory containing shader resources. The shader may reference a particular slot of the descriptor set using an offset, and may change shader resources by referencing a different slot of the descriptor set or by binding or rebinding a new descriptor set. A graphics pipeline may be specified by creating a pipeline object which specifies a shader and a rendering context object, and linking the pipeline object. Part or all of the pipeline may be validated, cross-validated, or optimized during linking.

Abstract: In a processing system including a plurality of graphics processing units (GPUs), the GPUs transfer compressed graphics streams composed of blocks of graphics data to one another. Some blocks of a compressed graphics stream, or parts thereof, may contain both compressed graphics data and meaningless data (referred to as data structure padding, or padding) that is used to align the graphics data, and some blocks may contain only padding. Before transferring a compressed graphics resource from one GPU to another GPU, the sending GPU compacts the compressed graphics resource by filtering out padding from the compressed graphics stream prepared for the transfer.

Abstract: Systems, apparatuses, and methods for implementing fine-grain power management for virtual reality (VR) systems are disclosed. A VR compositor monitors workload tasks while rendering and displaying content of a VR application. The VR compositor determines the priorities of different tasks of a given VR frame and cause power states to be assigned to processing units to match the priorities of the tasks being performed. For example, if a first task within a first frame period is assigned a high priority, a processing unit executing the task operates at a relatively high power performance state when performing the first task. If a second task within the first frame period is assigned a low priority, the processing unit operates at a relatively low power performance state when performing the second task. By implementing fine-grain power management in a VR environment, the likelihood of the processing unit suffering a thermal event or impaired performance is reduced.

Abstract: Systems, methods and apparatuses of processing data of a VR system are disclosed that comprise receiving tracking information which includes at least one of user position information and eye gaze point information. One or more processors may be used to predict, based on the user tracking information, a user viewpoint of a next frame of a sequence of frames of video data to be displayed. Using the prediction, a portion of the next frame of video data to be displayed is rendered at an estimated location in the next frame. A corresponding matching portion in a previously encoded frame is determined based on the estimated location of the portion in the next frame and the portion of the next frame of video data is encoded.