Performance of deferred and forward shading under different lighting conditions

ABSTRACT: The field of 3D computer graphics deals with ways of generating 2D images from 3D scene representations. This process is called rendering and its performance is one of the central problems in the field. Understanding performance implications of 3D graphics algorithms and testing them in different scenarios enables professionals in game, film, scientific and military industries to make informed decisions on which algorithms are best suited for their problem. In this thesis a close look was taken at performance of two most popular rendering approaches in real-time 3D graphics – deferred shading and forward shading. We investigated four different scenarios: many small lights, many big lights, many big lights with shadows and a mixed case of many small lights along with several big shadow-casting lights. Deferred shading showed better performance than forward shading in all tests, with the biggest gain obtained in case of having high numbers of small lights. When shadow-casting lights were present, the difference in performance, although significant, was not as hugely different as in case of small lights alone. Keywords: 3D Computer Graphics, Rendering, Deferred Shading, Forward Shading …………………………………………………………………………………………………………………………………………………………………………………………………………