This paper proposes a computational method for visualizing animated human reactions to physical conditions that are described in a synthetic architectural model. Its goal is to add a sense of place to the geometry, and augment the representation of its spatial quality for designers and audience. Spatial qualities in architectural design cannot be fully evaluated solely by observing geometrical constructs without reference to inhabitants placed inside. However, imagining what happens to those inhabitants and appreciating their movement is difficult even for trained architects. The proposed method introduces a walking scale figure in a geometric model. Through agent-based computation, it moves inside the model and displays various behaviors in reaction to spatial characteristics such as transparent surface, opaque surface, perforation and furniture. This method lays a foundation for developing a new kind of software that overcomes the shortcomings of current design tools.