Caustic rendering plays an important part in the research of photorealistic image rendering. Based on programmable GPUs

image-based photon mapping renders fast but suffers from artifacts caused by sampling and computing approximately. To overcome this drawback

this paper proposes a fast method called virtual object-based photon beam tracing (VOBPBT) to render caustic effects. VOBPBT originally defines the photon-path map and then constructs the map. It also presents a way to find caustic triangles in the photon-path map and splat them onto the caustic map. This method can recursively render reflective and refractive effects as well as high-frequency caustic effects realistically in an interactive speed. VOBPBT is useful in interactive computer-aided simulation

computer games

as well as virtual tours.