(A) method to propagate area light illumination through a layered depth image via warping

Abstract

An image-based method is proposed in this thesis, which is used for propagating area light illumination through a Layered Depth Image (LDI) to generate soft shadows from opaque and non-refractive transparent objects. In the proposed approach, using the depth peeling technique, an LDI from a reference light sample on a planar light source is rendered. Light illumination of all pixels in an LDI is then determined for all the other sample points via warping, an image-based rendering technique, which approximates ray tracing in the proposed method. An image-warping equation and McMillan’s warp ordering algorithm is used to find the intersections between rays and polygons and to find the order of intersections. Experiments for opaque and non-refractive transparent objects are presented. Results indicate the proposed method generates soft shadows fast and effectively. Advantages and disadvantages of the proposed method are also discussed.