Disclosed herein is a method of graphically presenting an indicating marker over a 3-D model of a tissue surface during a catheterization procedure, comprising determining a region over the 3-D model, deforming the indicating marker to congruently match a shape defined by the 3-D model across the region at a plurality of positions; and rendering the 3-D model into an image including the deformed indicating marker by generating an image of the 3-D model covered by said deformed indicating marker.