Acceleration radiosity solutions through the use of hemisphere-base formfactor calculation

In this paper, we propose a novel formfactor calculation algorithm for acceleration radiosity solutions in complex environments. Our basic algorithm is an improved version of Spencer's (S.N. Spencer, ‘The hemisphere radiosity method: a tale of two algorithms’, in Photorealism in Computer Graphics, Spencer, 1992, pp. 127–135) and Van Wyk's (G.C. Van Wyk Jr., ‘A geometry-based insolution model for computer-aided design,’ Ph.D. Thesis, The University of Michigan, 1998.) methods, which fail to remove hidden surfaces for relatively large patches and cause large discretization errors in formfactors. We also demonstrate that our technique is superior to the hemi-cube method in terms of the computation time. Moreover, we parallelize our approach on a parallel computer with shared memory, and obtain a high performance with our radiosity rendering system. Our method divides a hemisphere-base into regions, and assigns a region to each processor. The approach can be applied to geometrical data generated by CAD systems, and is evaluated in terms of the computation time, the visual effects, and the parallelization performance. © 1998 John Wiley & Sons, Ltd