Multiple processor visibility search system and method

A method for displaying visible objects on a display device, the method comprising:

• storing a bound hierarchy and a cone hierarchy in a shared memory;
• a plurality of processors reading bounds from the bound hierarchy and cones from the cone hierarchy and searching the cones with respect to the bounds to identify one or more nearest objects for the cones in the cone hierarchy;
• said processors providing indications of the one or more nearest objects for each of said cones to a rendering agent;
• said rendering agent generating pixel data in response to said nearest object indications and transmitting the pixel data to a display device.

A computer-readable memory medium for storing program instructions, wherein said program instructions are executable by each processor in a collection of processors to implement the operations of:

• reading a first bound-cone pair from a shared memory, wherein each bound-cone pair points to a corresponding first bound in a bound hierarchy and a corresponding first cone in a cone hierarchy;
• computing a bound-cone distance between the first bound and the first cone;
• determining if the bound-cone distance is smaller than a first visibility distance associated with the first cone;
• writing two or more second bound-cone pairs to the first problem queue in response to (a) the bound-cone distance being smaller than the first visibility distance, and (b) the first bound being a non-terminal bound of the bound hierarchy or the first cone being a non-terminal cone of the cone hierarchy;
• updating (c) the first visibility distance of the first cone with the bound-cone distance and (d) a nearest object indicator for the first cone with a pointer associated with the first bound in response to (e) the bound-cone distance being smaller than the first visibility distance and (f) the first bound being a terminal bound and the first cone being a terminal cone;
• wherein the nearest object indicators of the leaf cones of the cone hierarchy are usable to generate a rendered image on a display device.