Lett=φ (x, y, z) be an ore grade function sampled at the nodes of a three dimensional regular grid. Ift 0 is a given cut-off, the ore deposit may be considered to be constituted by all the points (x, y, z) such that φ(x, y, z)>t 0. In fact, the ore deposit may be constituted by one or several disconnected bodies and two algorithms to display these bodies may be considered. The first consists in drawing intersections of the bodies with a series of equidistant parallel planes. The second consists in covering their surface with “painted” triangles. In both cases, how to remove hidden parts of the drawing is shown. An interactive approach of the problem also is considered.