Abstract: An approach for implementing an approximation of a radiosity solver that may be run entirely in the graphics processing unit of a video game console is provided. A set of raw triangles is partitioned into a collection of roughly planar transfer patches. For each patch, a projection on to the direct product is defined and mapped into the radiosity UV space. A transfer bundle set is constructed by sorting visible patches by flux contribution and storing a predetermined number of the greatest contributors in a texture. At runtime, real-time global illumination is implemented by rendering direct lighting into a texture of the same resolution as the transfer bundle set. The lighting is successively propagated in a number of passes using the transfer bundles. Each pass constitutes a single “bounce” and the per-bundle contribution of the first bounce is extracted and used for an indirect specular and diffuse bump-mapping response.

Abstract: Arrangements are provided for real-time variable compression and decompression schemes. In one arrangement, compressed images are stored as collections of tiled line textures representing breadth-first trees. In another arrangement, an image is decompressed directly on a GPU employing a microcode pixel shader. The arrangements allow for variable compression that can take into account complex local variations in light and shadowing. In this way, areas of high contrast may have significant detail preserved. The arrangement may be employed in a number of applications, including real-time shader image decompression, lighting and relighting, static shadow maps, dynamic texture packing, geometric representations, displacement maps, and so on.

Abstract: An approach for implementing an approximation of a radiosity solver that may be run entirely in the graphics processing unit of a video game console is provided. A set of raw triangles is partitioned into a collection of roughly planar transfer patches. For each patch, a projection on to the direct product is defined and mapped into the radiosity UV space. A transfer bundle set is constructed by sorting visible patches by flux contribution and storing a predetermined number of the greatest contributors in a texture. At runtime, real-time global illumination is implemented by rendering direct lighting into a texture of the same resolution as the transfer bundle set. The lighting is successively propagated in a number of passes using the transfer bundles. Each pass constitutes a single “bounce” and the per-bundle contribution of the first bounce is extracted and used for an indirect specular and diffuse bump-mapping response.

Abstract: Arrangements are provided for real-time variable compression and decompression schemes. In one arrangement, compressed images are stored as collections of tiled line textures representing breadth-first trees. In another arrangement, an image is decompressed directly on a GPU employing a microcode pixel shader. The arrangements allow for variable compression that can take into account complex local variations in light and shadowing. In this way, areas of high contrast may have significant detail preserved. The arrangement may be employed in a number of applications, including real-time shader image decompression, lighting and relighting, static shadow maps, dynamic texture packing, geometric representations, displacement maps, and so on.

Abstract: A honing stone and guide assembly is described comprising an abrasive honing stone bonded to a plastics shoe. The shoe is a snap fit on the platform of a stone holder. A similar plastic snap-on honing guide fits a platform of a guide holder.

Abstract: A honing machine has a stone expansion system in which the honing stones are expanded radially via wedges by radial movement generated by a d.c. wedge motor. The motor (13) is driven by a constant-current amplifier (50) which provides a driving current according to a required stone pressure (a). This determines the torque of the motor during honing. A speed input (g) sets a required approach speed and from this is derived a control signal which controls an on/off controller (55). This causes the output current of the constant-current amplifier to be choppped, therby controlling speed as the stones approach the wall of the bore while allowing control of torque during honing.

Abstract: A honing machine in which a micro-processor controls reciprocation with respect to a work-piece of a spindle which carries honing stones, the micro-processor being associated with a memory unit which holds an acceleration profile in terms of position/time and being programmed to control reciprocation in accordance with the required acceleration characteristics. Variable stroke parameters and required mid-stroke speed are input from a console and the system ensures symmetrical honing under controlled acceleration regardless of any conflict between selected stroke length and mid-stroke speed.