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Reviewer: Burkhard Claus Wuensche

Three-dimensional (3D) models and animation are found in an increasing number of applications, ranging from games, movies, and advertisements to education, training, and social media (for example, Second Life ). The free open-source software Blender has enabled many people to create 3D content and publish it as (artistic) still images, animations, simulations, movies, and games. This book gives a good introduction to Blender and its wide range of functionalities. The book starts with a review of the history of Blender (chapter 1) and an overview of Blender's interface (chapter 2). This is very helpful-the Blender interface is often regarded as nonintuitive, and the many options result in a steep learning curve. Chapters 3 to 6 introduce techniques for creating 3D models and making them attractive. They cover modeling techniques, including direct mesh editing, sculpting, extrusion surfaces, surfaces of revolution, parametric curves, and nonuniform rational basis splines (NURBS). Subdivision surfaces are not mentioned explicitly, but are referred to in terms of rounding (beveling) and mesh smoothing. An explanation of lighting and texturing techniques enables the reader to add surface details and realistic visual effects, such as lighting and shadowing. Chapters 7 and 8 cover rigging and skinning-that is, associating a surface mesh with a hierarchical skeleton-and show how this can be used to animate a character. Chapter 9 explains how the techniques presented so far can be used to create a movie. This involves rendering animation frames, combining images, adding special effects using image processing techniques (for example, greenscreen filtering), and sequencing frames. Chapter 10 introduces physics-based special effects, including particle systems (explosions and hair), fluid simulations (water and smoke), and simulations of soft bodies and fabric. Chapter 11 gives a short overview of the Blender game engine and rigid body dynamics, and provides some examples of how the previously introduced concepts can be used to create a simple game. Chapter 12 concludes with a discussion of common problems, frequently asked questions (FAQs), and useful resources. One of the strongest points of the book is that it explains concepts in a very easy and intuitive manner, without any technical (mathematical) details. This makes the book suitable for absolute beginners with no knowledge of computer graphics and programming. The book is well structured, and each chapter ends with multiple examples that enable users to create attractive models, animations, and games. (I really enjoyed creating a face texture from photos; creating a walking animation; creating a facial animation and synchronizing it with a sound file; and augmenting a video of a real scene with virtual objects.) All of the explanations are supported with numerous pictures and exact explanations of which keys to press, which menu items to choose, and how to move the mouse. Furthermore, the author anticipates that users occasionally make mistakes and thus gives many tips on how to reverse them. The FAQs and resources in chapter 12 will enable readers to extend their knowledge and benefit from Blender's large user community. Additional useful resources are found throughout the book-including, for example, uniform resource locators (URLs) for existing rigs that readers can use for character animations. The book benefits from the practical experience of the author. For example, most rendering techniques for virtual environments do not scatter light, resulting in sharp contrasts and overly dark regions. The author demonstrates how different lights can be combined to get a more balanced illumination with smooth shadows and lighter contrasts. In another really important section, the author demonstrates how a low-resolution mesh and an associated displacement map can represent a high-resolution mesh much more effectively. I also really liked the reverse food rig, which is a great example of a model without physical motivation that works well from an animator's or artist's point of view. The book's strength-the avoidance of technical details-is also one of its weaknesses. In many instances, concepts are explained in a case-specific manner, which might be insufficient for readers to fully appreciate and use these technologies. For example, on page 43, the author talks about edge loops that follow the organic shape. It would be better to say that meshes should consist of many long stripes and that mesh parameter directions should be aligned with skeleton coordinate systems or virtual muscles. These rules result in faster rendering and the reduction of mesh distortions during animation. In several cases, pictures show meshes with curved edges (for example, Figure 3-44), which is confusing since polygons always have straight edges. Most likely these images show either the control mesh of a parametric surface, a subset of the edges of an underlying high-resolution mesh, or the edges corresponding to the base mesh of a subdivision surface. In any case, the displayed wireframe mesh does not represent a low-resolution polygon mesh. The author often refers to GLSL mode, but doesn't explain what it is and why it is important. Instead of saying "a half-decent graphics card should [provide] support," it would be better to give a more precise specification-for example, which DirectX or OpenGL versions must be supported by the card__?__ The difference between procedural textures and 2D textures (page 97) should be made clearer. A 2D texture with UV mapping is not more accurate, but it gives the user more control because the user can associate image pixels with 3D locations. In procedural textures, the texels are associated with 3D world coordinate points. This is useful when creating a carved appearance, which would be very difficult to achieve with UV mapping. I also would have liked to see more information about procedural textures and the many effects that can be created with them (for example, wood, clouds, and marble). The explanation of NURBS curves is very intuitive: control points are like magnets pulling the curve. Figure 6.33 claims that the NURBS version of a Coke bottle has fewer points than the surface of revolution. Note, however, that the figure shows only the control points of the surface, whereas rendering the surface requires either subdividing into smaller polygons or ray tracing the NURBS surface directly. Both alternatives are more time consuming than ray tracing a polygon mesh. It is also important to mention that parametric curves, such as Bézier curves and B-splines, can never represent a perfect circle since they are cubic. Hence, a user starting with a simple curve and arranging control points in a square pattern would not end up with a true circular shape. Fortunately, Blender has already predefined Bézier and NURBS circles, which use homogeneous coordinates and thus result in a perfect circle. Overall, this is an excellent book for beginners without any computer graphics and programming experience. Technical and mathematical details are avoided, which might disappoint readers who want to gain more insight into the underlying algorithms. However, I enjoyed reading the book and gained many new ideas from it. I hope that any future edition comes with an accompanying CD containing some of the more complex examples (including walking animation, facial animation for speech, and movie production). Online Computing Reviews Service