This paper describes an animation approach where synthetic vision is u
sed for navigation by a digital actor. The vision is the only channel
of information between the actor and its environment and offers a univ
ersal approach to pass the necessary information from the environment
to an actor in the problems of path searching, obstacle avoidance, and
internal knowledge representation with learning and forgetting charac
teristics. For the general navigation problem, we propose a local and
a global approach. In the global approach, a dynamic octree serves as
global 3D visual memory and allows an actor to memorize the environmen
t that he sees and to adapt it to a changing and dynamic environment.
His reasoning process allows him to find 3D paths based on his visual
memory by avoiding impasses and circuits. In the local approach, low-l
evel vision-based navigation reflexes, normally performed by intellige
nt actors, are simulated. The local navigation model uses the direct i
nput information from his visual environment to reach goals or subgoal
s and to avoid unexpected obstacles.