We present a multilevel object modeling scheme adapted to storage and progressive transmission of complex 3D objects. Geometry and texture are encoded in terms of surface particles associated to a hierarchical space partitioning via an OC-tree. Proper ordering of surface particles results in a compact multilevel representation without increasing the size of the uni-resolution model which provides the highest level of detail. This compact representation can be progressively decoded by the viewer, and transformed by a fast direct triangulation technique into a sequence of triangle meshes of increasing levels of detail. The proposed scheme is demonstrated with 3D models of real objects constructed by a shape from silhouette technique.