Methods, apparatus and computer software products implement embodiments of the present invention that include applying energy to a probe that is in contact with tissue in a body cavity so as to ablate the tissue. While applying the energy, signals are received from a location transducer in the probe, which are indicative of a location of the probe in the cavity. The signals are processed so as to derive 3D location coordinate points corresponding to the location of the probe at a sequence of times during which the energy was applied. While applying the energy, a 3D representation of the body cavity is rendered to a display, and visual indicators are superimposed on the 3D representation, the visual indicators corresponding to the 3D location coordinate points at the sequence of times. Finally, a linear trace connecting the coordinate points in accordance with the sequence is superimposed on the 3D representation.