Abstract: A SIMD processing unit processes a plurality of tasks which each include up to a predetermined maximum number of work items. The work items of a task are arranged for executing a common sequence of instructions on respective data items. The data items are arranged into blocks, with some of the blocks including at least one invalid data item. Work items which relate to invalid data items are invalid work items. The SIMD processing unit comprises a group of processing lanes configured to execute instructions of work items of a particular task over a plurality of processing cycles. A control module assembles work items into the tasks based on the validity of the work items, so that invalid work items of the particular task are temporally aligned across the processing lanes. In this way the number of wasted processing slots due to invalid work items may be reduced.

Abstract: There is provided a method and apparatus for managing memory in a system for generating 3-dimensional computer images. The image is subdivided into a plurality of rectangular areas. A memory is provided and a page of the memory is allocated for storing object data for objects in the image. Object data for objects in the image are then written to the allocated page of memory. Finally, a bit mask for the allocated page of memory is compiled, the bit mask indicating the rectangular areas having object data stored in the allocated page of memory. A rectangular area of the image can then be rendered by deriving data for display from the object data stored in the memory, for objects in that rectangular area. Once the rectangular area has been rendered, the bit mask for each page of memory which stored, before the step of rendering, object data for that rectangular area, is updated so that the bit mask no longer indicates that rectangular area.

Abstract: There is provided a method and apparatus for managing memory in a system for generating 3-dimensional computer images. The image is subdivided into a plurality of rectangular areas. A memory is provided and a page of the memory is allocated for storing object data for objects in the image. Object data for objects in the image are then written to the allocated page of memory. Finally, a bit mask for the allocated page of memory is compiled, the bit mask indicating the rectangular areas having object data stored in the allocated page of memory. A rectangular area of the image can then be rendered by deriving data for display from the object data stored in the memory, for objects in that rectangular area. Once the rectangular area has been rendered, the bit mask for each page of memory which stored, before the step of rendering, object data for that rectangular area, is updated so that the bit mask no longer indicates that rectangular area.

Abstract: A method for texturing and shading a 3D computer graphic image on shading engines. First, the image is subdivided into tiles and each tile is subdivided into micro tiles. An object list is allocated to each tile, the object list containing data defining objects visible in the tile. For one micro tile, it is determined which pixels in the micro tile are intersected by an object A in the object list and it is determined which pixels in the micro tile are intersected by at least one other object in the object list. In parallel with the determination step, pixel intersection data is outputted for an object B for which all intersection determinations for each of the micro tiles in a selected tile have been performed. The pixel intersection data is output to at least one of the shading engines.

Abstract: There are provided methods and apparatus for generating a 3-dimensional computer image. The image includes a number of objects and is divided into separate areas. Control data to link to object data stored in a memory for each object is derived for two objects at a time. Two or more separate areas can be processed in parallel by deriving control data for the two separate areas at a time. To avoid fetching data for both areas, which is actually only applicable to one area, encoding is used in the control data. The object data can be stored on one or across two memory pages, and the control data includes one memory page address in the former case and two memory page addresses in the latter case. The object data can also be stored across two non-contiguous memory pages, by using a look-up table with contiguous portions allocated for each object's object data.

Abstract: Memory management system and method for use with systems for generating 3-dimensional computer generated images are provided.

Abstract: There is provided a method for texturing and shading a 3D computer graphic image on a plurality of shading engines. First, the image is subdivided into a plurality of tiles and each tile is subdivided into a plurality of micro tiles. An object list is allocated to each tile, the object list containing data defining objects visible in the tile. For one micro tile, it is determined which pixels in the micro tile are intersected by an object A in the object list and it is determined which pixels in the micro tile are intersected by at least one other object in the object list. In parallel with the determination step, pixel intersection data is outputted for an object B for which all intersection determinations for each of the micro tiles in a selected tile have been performed. The pixel intersection data is output to at least one of the plurality of shading engines. Then, those steps are repeated for each micro tile in the selected tile in which there are visible objects.

Abstract: There is provided a method and apparatus for managing memory in a system for generating 3-dimensional computer images. The image is subdivided into a plurality of rectangular areas. A memory is provided and a page of the memory is allocated for storing object data for objects in the image. Object data for objects in the image are then written to the allocated page of memory. Finally, a bit mask for the allocated page of memory is compiled, the bit mask indicating the rectangular areas having object data stored in the allocated page of memory. A rectangular area of the image can then be rendered by deriving data for display from the object data stored in the memory, for objects in that rectangular area. Once the rectangular area has been rendered, the bit mask for each page of memory which stored, before the step of rendering, object data for that rectangular area, is updated so that the bit mask no longer indicates that rectangular area.

Abstract: There are provided methods and apparatus for generating a 3-dimensional computer image. The image comprises a number of objects and is divided into separate areas. In a first aspect, control data to link to object data stored in a memory for each object is derived for two objects at a time. This improves processing and memory usage. In a second aspect, two or more separate areas can be processed in parallel by deriving control data for the two separate areas at a time. This improves processing time. To avoid fetching data for both areas, that is actually only applicable to one area, encoding is used in the control data. In a third aspect, object data can be stored on one or across two memory pages, and the control data includes one memory page address in the former case and two memory page addresses in the latter case. This improves memory usage.

Abstract: Memory management system and method for use with systems for generating 3-dimensional computer generated images.

Abstract: An interface for use in a 3-d graphics system comprising a parametric modelling unit for modelling objects as high order surfaces, and a polygon based rendering system for rendering polygon modelled objects for display. The interface comprises an input for receiving data and a subdivision unit coupled to the input for processing the data. The interface includes a converter coupled to the subdivision unit for determining from leaf patch data a first plurality of values representing vertices of tessellating polygons describing the leaf patch, and for determining from sub-leaf patch data a second plurality of values representing the vertices of tessellating polygons describing the sub-leaf patch. The interface also has a combiner, coupled to the converter, for combining the values to form leaf polygon data defining the polygon vertices at a first subdivision level, and an output coupled to the combiner for outputting the leaf polygon data.

Abstract: An interface for use in a 3-d graphics system comprising a parametric modelling unit for modelling objects as high order surfaces, and a polygon based rendering system for rendering polygon modelled objects for display. The interface comprises an input for receiving data and a subdivision unit coupled to the input for processing the data. The interface includes a converter coupled to the subdivision unit for determining from leaf patch data a first plurality of values representing vertices of tessellating polygons describing the leaf patch, and for determining from sub-leaf patch data a second plurality of values representing the vertices of tessellating polygons describing the sub-leaf patch. The interface also has a combiner, coupled to the converter, for combining the values to form leaf polygon data defining the polygon vertices at a first subdivision level, and an output coupled to the combiner for outputting the leaf polygon data.

Abstract: A method and apparatus for shading 3-dimensional computer generated images represents each object in the image as a set of polygons. An image plane on which the image is to be displayed is divided into a plurality of rectangular areas. Data defining the location of each polygon is then supplied. The rectangular areas which are required to show the whole of the polygon are then determined. Then, for each pixel in each rectangular area, the depth value is determined for the distance of a surface of the polygon from the image plane and a determination is made as to whether or not the surface is visible at that pixel. The pixel is shaded on dependence on the result of this determination.