Incorporating both historical techniques and the most recent developments in computer graphics, Shader Writing in Open Shading Language is a treatise on OSL shader writing and shader development that intends to remedy the current lack of material on this important area of technical and artistic expertise. It is for artists who wish to know more about shaders and shader writing, for programmers who want the ultimate in creative control, or for anyone in‑between. It begins by covering the entire range of independent variables upon which all shaded pattern generation is based. From that foundation, every fundamental procedural, textural, conversion, and pattern modification shader category is described with clear and practical examples. Each topic is presented in a progression of chapters that begin with the fundamentals and expand to more complex shaders illustrating more advanced techniques that build on the previously covered material. In addition, these important topics are also covered: Shader user interface design and parameter widgets Color, color models, color spaces, and color transformations 2d and 3d spaces and their transformations Texture patterns Ray tracing for pattern generation Displacement and bumped shading normal generation Shader organization, building, and deployment Shader execution and debugging