The difficulty lies in the complexity must simultaneously consider many system goals, some of them contradictory. The book is organized so that follow a spiral development process for each stage, explaining the problem and possible solutions for each stage. Much more hands-on than other introductory books, concrete examples and practical solutions to technical challenges in building a VR system are provided. Part 1 covers the very basics in building a VR systemand explain various technical problems in the modeling of object and scene organization.