TOP  >  Thesis/Dissertation  >  The Estimation of the Shape and Bidirectional Reflectance Distribution Function of Objects under Tyndall Effect

The Estimation of the Shape and Bidirectional Reflectance Distribution Function of Objects under Tyndall Effect

Recently, realistic CG is used for movies, news shows, and animations. Creating realistic CG by hand costs enormously, so there are increasing demands for creating realistic CG automatically. 3D shape and reflection characteristics measured from real objects are necessary for creating realistic CG. The reflection characteristics are usually described as Bidirectional Reflectance Distribution Function (BRDF). Some methods for estimating the 3D shape and BRDF of objects are proposed. They estimated the shape and BRDF by irradiating the object and capturing the reflected light with cameras. However, they cannot estimate the 3D shape of the objects such as black objects or metal objects if cameras cannot capture the reflected light. We propose the method to estimate the 3D shape of such objects. To overcome the problem of no capturing the reflected lights by the cameras, we take advantage of Tyndall effect. Under Tyndall effect, we can observe directly the incident and reflected light from any view points. This is because the particles let the light scatter. Observing the line of incident light under Tyndall effect, we can estimate the 3D shape of objects as the reflection point where the light broke off. In addition, we can capture scattered light of the reflection at the surface of objects and estimate the BRDF of objects as non-parametric BRDF model. In this study, we describe BRDF by Lambert model and Torrance-Sparrow model and estimate the parameters. We evaluated the effectiveness of the proposed method, estimating the 3D shape and reflection characteristics of a metal object and a black object.