Reusable Radiosity Object

Because of the view independence and photo realistic image generation in diffuse environment, radiosity is suitable for an interactive walkthrough system. The drawback is time-consuming in form factor estimation, and furthermore, inserting, deleting or moving an object makes the whole costly rendering process repeat. To solve this problem, we encapsulate necessary information for form factor calculation and visibility estimation in each object, which is called a reusable radiosity object. Whenever a scene updates, the radiosity algorithm looks up the prestored information in each object, thus speeds up by two orders of magnitude. Besides, solution time based on cluster representatives is linear to the number of objects since each object is reusable, encapsulated with preprocessed data in every level of hierarchy. We also analyze the unregarded error on visibility estimation and propose a statistically optimal adaptive algorithm to maintain the same error for each link.