关键词: 协同虚拟环境, 交互, 集合论, 化身

Abstract: Interaction is one important technology of multi-sense intercommunion and collaboration between user in collaborative virtual environments.At present，because of lack of researching the interactive technology systemically and comprehensively，the depth of interaction in virtual geographic environments is obvious insufficient，which effects the efficiency of collaborative work greatly.Therefore，the set theory is introduced into the interaction technology of virtual geographic environments firstly in the paper.According to different interacted objected，the complicated interaction is analyzed and researched systemically，which is divided into six types of interaction by using the set theory.On the basis，the Agent technology is used to construct the intelligent semantic object model in order to helping the execution of interaction efficiently.And the VTK and Cal3D development package is applied to construct the virtual geographic environments system and implement the multi-interaction between avatars and intelligent objects.

Key words: collaborative virtual environments, interaction, set theory, avatar