Illuminating Crowds Via Integral Approximation of Cosine Lobes

Real time crowd rendering has long been the subject of intense research, which has led to many advancements in the field. The research up until now has either focused on increasing the number of virtual people rendered or on the reduction of the inherit homogeneity of real time crowds. With the rapid advances of technology, people’s expectations of rendering realism have increased significantly. This means that simply rendering large varied crowds is no longer sufficient. Therefore more advanced rendering methods must be adopted so as to increase the realism of the rendered virtual people. This paper introduces a new illumination technique developed for the use in real-time crowds. This is achieved by using the approximations of cosine lobe integrals together with environment maps, allowing a more realistic rendering of crowds. The approximations are shown to have a low error, whilst maintaining interactive frame rates when used within a crowd. Furthermore, the rendering of the crowd is improved due to more realistic rendering approach which allows diverse BRDFs to be applied to the differing materials within each virtual human.