1. A method for influencing a depiction of a three-dimensional object that is displayed using volume rendering, the method comprising: providing a representation of the object, in which values of a variable characterizing the object are given at spatial points of the object, and in which color values are allocated to the variable during the course of the volume rendering; inputting a set of points defined in the space of the representation of the object, calculating a distance from the spatial points in the representation of the object to the set of points; determining the color values allocated to the spatial points according to the calculated distance; and calculating a depiction of the object by the volume rendering, using the representation of the object, wherein the representation comprises the determined color values.