The 3D viewer is more than a 3D visualization application. It was designed to serve as a high-level programming library for 3D visualization, especially for the visualization of 3D biomedical images.
The document in hand is intended to provide a set of examples and use-cases. The HowTo’s are ordered with increasing complexity. Each HowTo itself starts by explaining a basic example, referring to example code. The example code can be downloaded from the Examples’ site. Each HowTo then continues to describe more detailed aspects, as well as other background information.
The fastest way to get started is to look at the examples, which should be pretty much self-explaining. For the features of interest, it is recommended to read the corresponding HowTo.