Top tree

Abstract: A motorcycle fork tree assembly includes a steering axle attached to a top tree piece and a bottom inner tree piece. The bottom inner tree piece is pivotally secured to a bottom intermediate tree piece which is adjustably positioned within a bottom outer tree piece. The fork tubes extend through the bottom outer tree piece and are attached to the top tree piece via plugs having offset bores positioned in one of a number of threaded holes of the top tree piece. The degree of trail of the steering assembly for the motorcycle can be easily and quickly adjusted by the independent adjustment of one or more of the bottom outer tree piece relative to the bottom inner tree piece or the plugs in the top tree piece.

Abstract: We present an algorithm, called Bonsai, for rapidly building bounding volume hierarchies for ray tracing. Our method starts by computing midpoints of the triangle bounding boxes and then performs a rough hierarchical top-down split using the midpoints, creating triangle groups with tight bounding boxes. For each triangle group, a mini tree is built using an improved sweep SAH method. Once all mini trees have been built, we use them as leaves when building the top tree of the bounding volume hierarchy. We also introduce a novel and inexpensive optimization technique, called mini-tree pruning, that can be used to detect and improve poorly built parts of the tree. We achieve a little better than 100% in ray-tracing performance compared to a "ground truth" greedy top-down sweep SAH method, and our build times are the lowest we have seen with comparable tree quality. (Less)

Abstract: One embodiment of the present invention provides a method and a system for performing a nearest-neighbor matching operation using a parallel hybrid spill tree. During operation, the system receives an object to be compared to a set of objects stored in the parallel hybrid spill tree. The system first searches a “top tree” of the parallel hybrid spill tree to identify a partition that is likely to contain a nearest neighbor of the object. Each node in the top tree defines an associated partition for the parallel hybrid spill tree. The system then searches a “leaf sub-tree” of the parallel hybrid spill tree that corresponds to the associated partition in an attempt to identify the nearest neighbor of the object.