Image-based Occluder Selection: an Introductory Overview

In many cases complex scenes are composed of densely occluded objects, which means that only a small fraction of the scene is visible, while the remaining parts are occluded. This property can be exploited to accelerate rendering by simply removing most of the hidden parts before sending the polygons to the graphics hardware. In recent years, a lot of so called occlusion-culling methods have been proposed to speed up real-time rendering that way. A common prerequisite to many of these methods are fast occluder selection algorithms. This work focuses on a novel approach to determine nearly optimal occluder objects with respect to arbitrary scenes. The selection is based on the examination of an early low-resolution image of the scene, which is rendered by a simple image-based rendering technique. The accuracy of the resulting image is still too low for an exact determination of the visible objects in the final image, but sufficient for improved occluder selection.