Systems, methods and apparatuses may provide for technology to reduce rendering overhead associated with light field displays. The technology may conduct data formatting, re-projection, foveation, tile binning and/or image warping operations with respect to a plurality of display planes in a light field display.

A method and system is provided for culling hidden objects in a tile-based graphics system before they are indicated in a display list for a tile. A rendering space is divided into a plurality of regions which may for example be a plurality of tiles or a plurality of areas into which one or more tiles are divided. Depth thresholds for the regions, which are used to identify hidden objects for culling, are updated when an object entirely covers a region and in dependence on a comparison between a depth value for the object and the depth threshold for the region. For example, if the depth threshold is a maximum depth threshold, the depth threshold may be updated if an object entirely covers the tile and the maximum depth value of the object is less than the maximum depth threshold.

A graphics processing system performs hidden surface removal and texturing/shading on fragments of primitives. The system includes a primary depth buffer (PDB) for storing depth values of resolved fragments, and a secondary depth buffer (SDB) for storing depth values of unresolved fragments. Incoming fragments are depth tested against depth values from either the PDB or the SDB. When a fragment passes a depth test, its depth value is stored in the PDB if it is a resolved fragment (e.g. if it is opaque or translucent), and its depth value is stored in the SDB if it is an unresolved fragment (e.g. if it is a punch through fragment). This provides more opportunities for subsequent opaque objects to overwrite punch through fragments which passed a depth test, thereby reducing unnecessary processing and time which may be spent on fragments which ultimately will not contribute to the final rendered image.

A depth processing method and associated graphic processing circuit is provided. The method comprises loading geometry data of a scene and performing a vertex transformation thereof. After the geometry data is segmented in a tile resolution, pre-depth data of the scene are obtained. After the geometry data are segmented in a bin resolution, plural bin tables are generated. Then, the plural bin tables are converted into plural tiles, the plural converted tiles are classified into a first portion of tiles and a second portion of tiles according to depth data of the converted tiles and the pre-depth data of the scene, and the second portion of tiles are discarded. After the first portion of tiles are processed, a color value and a depth value of each pixel of the scene are generated.

In position-only shading, two geometry pipes exist, a trimmed down version called the Cull Pipe and a full version called the Replay Pipe. Thus, the Cull Pipe executes the position shaders in parallel with the main application, but typically generates the critical results much faster as it fetches and shades only the position attribute of the vertices and avoids the rasterization as well as the rendering of pixels for the frame buffer. Furthermore, the Cull Pipe uses these critical results to compute visibility information for all the triangles whether they are culled or not. On the other hand, the Replay Pipe consumes the visibility information to skip the culled triangles and shades only the visible triangles that are finally passed to the rasterization phase. Together the two pipes can hide the long cull runs of discarded triangles and can complete the work faster in some embodiments.

Briefly, in accordance with one or more embodiments, a processor performs a coarse depth test on pixel data, and performs a final depth test on the pixel data. Coarse depth data is stored in a coarse depth cache, and per pixel depth data is stored in a per pixel depth cache. If a result of the coarse depth test is ambiguous, the processor is to read the per pixel depth data from the per pixel depth cache, and to update the coarse depth data with the per pixel depth data if the per pixel depth data has a smaller depth range than the coarse depth data.

Methods and coarse depth test logic perform coarse depth testing in a graphics processing system in which a rendering space is divided into a plurality of tiles. A depth range for a tile identifies a depth range based on primitives previously processed. A determination is made based on the depth range for the tile as to whether all or a portion of a primitive is hidden in the tile. If at least a portion of the primitive is not hidden in the tile, a determination is made as to whether the primitive or a primitive fragment thereof has better depth than the primitives previously processed for the tile. If so, the primitive or the primitive fragment is identified as not requiring a read of a depth buffer to perform full resolution depth testing, such that a determination that at least a portion of the primitive is hidden in the tile causes full resolution depth testing not to be performed on at least that portion of the primitive.

A graphics processing system has a rendering space which comprises one or more tiles. The system comprises a processing module configured to perform hidden surface removal for primitives of a tile to determine primitive identifiers identifying the primitives which are visible at each of a plurality of sample positions in the tile. A set of two or more tag buffers store the primitive identifiers determined for each of the sample positions in a tile, thereby representing overlapping layers of primitives. A tag control module controls: (i) selection of a tag buffer for the storage of each of the primitive identifiers according to the layering of the primitive identifiers stored in the tag buffers, and (ii) flushing of primitive identifiers from the tag buffers. A texturing engine applies texturing to the primitives identified by the flushed primitive identifiers.

Provided are a rendering method and a rendering apparatus performing the rendering method. The rendering method includes receiving a request to output a hierarchical depth value stored in a hierarchical depth buffer, outputting the hierarchical depth value from the hierarchical depth buffer, storing the hierarchical depth value, in response to the request, and performing rendering using the stored hierarchical depth value.

There is provided a scene rendering system and method for use by such a system to perform depth buffering for subsequent scene rendering. The system includes a memory storing a depth determination software including a reduced depth set identification software module, and a hardware processor configured to execute the depth determination software. The hardware processor is configured to execute the depth determination software to determine, before rendering a scene, a depth buffer based on at least one fixed depth identified for each element of a rendering framework for the scene. The hardware processor is further configured to render the scene using the depth buffer.