1. A method for generating a visual hull for an object, wherein the object is three-dimensional and the method comprises the steps of: extracting a set of silhouettes from a set of images, wherein there is one silhouette for each image; generating a set of convex polyhedra as a coarse 3D model of the object, wherein the coarse 3D model is obtained as a single convex polyhedron by intersecting all viewing cones corresponding to the 2D convex hull of each silhouette; refining the convex polyhedra by projecting the convex polyhedra to each image and determining the intersections with the silhouette in the image; and representing the visual hull of the object as union of the convex polyhedra, wherein the steps are performed in a processor.