Abstract: A method and apparatus for generating geometric data are to be used in the building of an object using a layer-by-layer additive manufacturing process. The method includes providing object data defining the object, identifying from the object data one or more regions of a surface of the object to be supported during the additive manufacturing process and, for the or each region, identifying one or more supporting structures that will provide support for the region and generating an arrangement of supports within the region. A support location of each support of the arrangement relative to the other supports of the arrangement is derived from a location of the supporting structures.

Abstract: The surface of a dental part is scanned by a probe, to obtain a digital model of the surface in a dental CAD computer system. In the digital model, first and second boundary lines are defined, above and below a portion in which the scanned data is missing or unsatisfactory. One of the boundary lines may correspond to a margin line between prepared and unprepared portions of the patient's tooth. A transition surface is generated in the computer system, extending between the first and second boundary lines. This improves the representation of the dental part in the digital model, which may subsequently be used for manufacture of a dental restoration.