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Reviewer: Adina Raclariu

The importance of radiosity in realistic image synthesis for design, engineering, and scientific applications is demonstrated. The book raises a lot of problems and presents a fascinating research subject. The volume is valuable for a wide range of readers because it provides an exhaustive approach to most problems that arise in handling various global illumination phenomena. This book surveys existing methods and presents new results in the field. Within the framework, some basic concepts are detailed or exemplified, extending the utility of the book to that of a classroom textbook. Radiosity is an essential component of the complex domain of computer vision. The first chapter establishes the place of radiosity in realistic image synthesis. For a scene whose geometry and material properties have been specified numerically, a model of light reflection and propagation can be evaluated. Radiosity is a departure for image synthesis and is viewed essentially as a finite element method. Chapter 2 describes rendering concepts. The general rendering equation, which expresses the conservation of light energy at all points in space, unifies the discussion of global illumination algorithms. The third chapter is concerned with a mathematical framework for approximately solving the radiosity integral through the solution of a system of linear equations, taking into account that integral equations are difficult to solve and numerical methods must be used. Chapter 4 addresses the computation of a form factor, which represents the geometric relationship between two surface areas. The fifth chapter enumerates several methods for solving linear systems that are applicable to the radiosity problem. It takes dynamic environments and the modifications in the radiosity algorithm into account. The next three chapters describe strategies and algorithms for subdividing the radiosity function into finite elements, with the goal of producing an efficient and accurate solution. The accuracy of the approximation is influenced by the size, shape, and orientation of the elements, as well by the polynomial order of the basis functions. Chapter 6 presents strategies for producing a good mesh and shows how various characteristics of the mesh affect accuracy. The accuracy of the approximation produced by a particular subdivision and the choice of basis functions determines the meshing type. The meshing strategies surveyed in this chapter are designed to reduce the computational cost of the solution by minimizing the number of elements in the mesh. In chapter 7, methods are developed that reduce the cost of radiosity algorithms, attempting to reduce the number of individual relationships, or form factors, that have to be computed. Chapter 8 discusses basic subdivision techniques for producing an initial uniform mesh. Topological data structures and how they can be applied to meshing are described. Finally, the authors present several alternatives to meshing that have been developed in order to avoid some of the complexities of surface subdivision. Chapter 9 focuses on image rendering. First, one finds an approximation from the radiosity solution that is more suitable for rendering. Techniques covered include hardware-assisted rendering and techniques for rendering texture using radiosity. The authors explain how to map radiance values resulting from the radiosity analysis to pixel values in order to produce a subjectively accurate image. This chapter concludes with issues relating to color perception and the selection of appropriate red, green, and blue pixel values to represent the visible spectrum. Chapter 10 presents approaches to lifting the restrictions to Lambertian diffuse reflection and non-participating media. Specialized light emitters, such as point lights, spot lights, and sky or natural light, are also discussed. The last chapter discusses some radiosity applications and possible future work, including architectural design, lighting design, remote sensing, visual shape understanding, infrared signature analysis, and fine arts. The book demonstrates that the radiosity method is useful, and encourages the reader to investigate details of the algorithms presented. Another fact that will have a major effect on future improvement of the radiosity method will be advances in technology, including parallel and other advanced computer architectures coupled with generally faster processors and larger memory capabilities. The references are adequate, complete, and topical.