Research into virtual environments on the one hand and artificial intellige
nce and artificial life on the other has largely been carried out by two di
fferent groups of people with different preoccupation and interests, but so
me convergence is now apparent between the two fields. Applications in whic
h activity independent of the user takes place-involving crowds or other ag
ents-are beginning to be tackled, while synthetic agents, virtual humans, a
nd computer pets are all areas in which techniques from the two fields requ
ire strong integration. The two communities have much to learn from each ot
her if wheels are not to be reinvented on both sides. This paper reviews th
e issues arising from combining artificial intelligence and artificial life
techniques with those of virtual environments to produce just such intelli
gent virtual environments. The discussion is illustrated with examples that
include environments providing knowledge to direct ol assist the user rath
er than relying entirely on the user's knowledge and skills, those in which
the user is represented by a partially autonomous avatar, those containing
intelligent agents separate from the user, and many others from both sides
of the area.