
Chapter 14
Geometric models of virtual
environments
Guillaume Moreau
14.1 INTRODUCTION
In a virtual environment, the observer moves in a world which is a representation of a
part of the reality or of an imaginary environment (Fuchs, 1996). In most of the cases,
the representation given to the observer is primarily visual. This visual representation
is formed by projecting a 3D geometric model of the virtual environment on one or
more flat 2D images using virtual cameras whose movements can be linked to the
observer’s movements.
This environment of course does not have only geometric elements. Let’s take
the example of a virtual city. A virtual city is