Book excerpt: The world around us is filled with subtle lighting effects, but until recently it was not possible to duplicate these real-world effects in computer games because of the limits of consumer graphics hardware. Advanced Lighting and Materials with Shaders explains the principles of lighting theory and discusses how to create realistic lighting that takes full advantage of the capabilities of modern hardware. Topics include the physics of light, raytracing and related techniques, objects and materials, lighting and reflectance models, implementing lights in shaders, spherical harmonic lighting, spherical harmonics in DirectX, and real-time radiosity.Upon reading this text, you will understand the underlying physics of light and energy; learn about the visual features of different materials and how they can be modeled for real-time graphics; find out about the different lighting models; discover how real-time techniques compare to ray tracing; learn to use the provided shader implementations to implement lights and realistic materials in real time.Accompanying CD-ROM includes all the code in the book with resources (models, textures, probes, etc.) needed to run the programs, along with the SDKs and libraries needed to build the programs and luminance Radiosity Studio, an advanced radiosity program.