The present invention is a system and method for graphically displaying a three-dimensional model of a region located within a living body. A three-dimensional model of a region of interest is displayed on a graphical display. The location in three-dimensional space of a physical characteristic (e.g. a structure, wall or space) in the region of interest is determined using at least one probe positioned within the living body. The graphical display of the model is deformed to approximately reflect the determined three-dimensional location of the physical characteristic. Preferably, the probe or probes are moved throughout the region of interest so as to gather multiple data points that can be used to increase the conformity between the graphical display and the actual region of interest within the patient.