Described embodiments include a system that includes a display and a processor. The processor is configured to modify an image that includes a representation of a wall of an anatomical cavity, by overlaying an icon that represents an intrabody tool on a portion of the image that corresponds to a location of the intrabody tool within the anatomical cavity, and overlaying a marker on a portion of the representation of the wall that corresponds to a location at which the intrabody tool would meet the wall, were the intrabody tool to continue moving toward the wall in a direction in which the intrabody tool is pointing. The processor is further configured to display the modified image on the display. Other embodiments are also described.