Metamorphosis or morphing is a technique to accomplish a gradual shape transformation between a source object and a target object. This technique is usually used for animation, i.e., to create some special effects, but it can be also employed as a modeling tool where some existing shapes are combined in order to obtain new shapes. Several interactive or automatic morphing techniques were designed in the past but always with a specific object representation in mind. In this paper we propose a generic framework for 3D morphing, that allows multi-resolution surface extraction and provides a hybrid (surface-volume) dynamic representation which is suitable for encoding the static models, for supporting different morphing methods, and for encoding the intermediate 3D frames (generated during the morphing process) in a MPEG-4 stream.