Patent ID: 6922563

Claim:
A shield detection method for detecting a shield shielding a ray that travels among a plurality of contents, wherein the plurality of contents are provided in a three dimensional observation space, and wherein the ray is radiated through said observation space, said method comprising: a first step of acquiring a first image of said ray projected onto a projected object preset within said observation space; a second step of, for each content, acquiring a second image of each content by projecting each content onto said projected object, thereby generating a plurality of second images, wherein each second image corresponds to a content; a third step of determining whether or not said first image intersects any of said second images; and a fourth step of including each content in a shield detection object group for said ray, if said third step indicates an intersection; wherein said first to fourth steps are iteratively repeated for one or more additional projected objects, and wherein said second step projects each content from said shield detection object group generated in a preceding iteration.