We present three ways to generate or select a shape that correctly satisfies specifications, that is a set of functional requirements. The first one consists in combining functional shapes satisfying the functional requirements, the second one in distorting an object in order to better and better satisfy the specifications. The last one simply consists in scanning the previously designed objects to select the one that best fits the new specifications. As the proposed shape can not perfectly satisfy the specifications, it is necessary to involve the designer during or after the generation process. We mention how this can be done with the first two approaches.