The illustrations in this book shouldn't be unfamiliar if you're a frequent visitor of 3D Total. The artwork can be found in the art galleries over there.
This book has compiled the working processes of more than 50 artists. It is not a step-by-step tutorial book and it doesn't focus on any specific software. But the frequently used software are 3D Max, Maya and Photoshop. The art techniques used by the artists can be easily achieved using similar software.
One illustration from each artist is chosen. The workflow of creating the illustration is then explained in first person by the artists. They talk about the challenges, tips, techniques and inspiration they have. For example, on the subject of creating realism in scenes, different artists will take different approaches. All these are discussed non technically that every reader should have no problem following.
The book focuses heavily on 3D art. However, there's a small section with several artists featured on 2D digital painting as well. For 3D, you'll read about things like how textures are applied, how lighting is handled, the different approaches to modeling etc. For digital painting, it's basically on the process and how they achieve the look they planned out in the concept stage.
This book is highly recommended to 3D and digital painting artists.