The inner volume of an inhomogeneous three-dimensional object is visualized by a plurality of simulated visual rays. For a respective visual ray entering the object volume, i) a scatter position is determined along the visual ray, ii) a scatter direction is selected in dependence on a random process, and iii) the visual ray is scattered at the scatter position in the selected scatter direction. Steps i) to iii) are repeated until the visual ray is absorbed in the object volume or exits the object volume, wherein the exiting visual ray is incident on an illumination source and, in dependence on a brightness and/or color value of the illumination source, an illumination contribution of the visual ray to a respective visualization pixel is ascertained.