In this paper we describe CALVIN, an immersive multimedia approach to applying virtual reality in architectural design and collaborative visualization emphasizing heterogeneous perspectives. These perspectives, including multiple mental models as well as multiple visual viewpoints, allow virtual reality to be applied in the earlier, more creative, phases of design, rather than just as a walk-through of the finished space. CALVIN's interface employs visual, gestural, and vocal input to give the user greater control over the virtual environment. A prototype of CALVIN has been created and used in the CAVE(tm) virtual reality theatre.