An apparatus for generating data representations of an object for additive manufacturing, the apparatus comprising: at least one processor to determine two-dimensional slices for each of a plurality of 3D models of objects, wherein the 2D slices are for coordinates along a slicing axis; and characterized in that : for each 2D slice of each 3D model, the processor is to: determine whether the 2D slice is complete or incomplete for additive manufacturing, wherein a 2D slice is determined to be complete when the boundary forms a closed polygon and is determined to be incomplete when it is determined that the boundary has a gap; in response to determining the 2D slices are complete, combine corresponding 2D slices of the plurality of 3D models for each coordinate according to a Boolean operation to generate combined 2D slices printable by an additive manufacturing system, wherein the Boolean operation comprises at least one of AND, OR, and XOR; and. in response to the at least one processor determining that at least one of the 2D slices is incomplete, generating an indication of a defective 3D model. at least one processor to determine two-dimensional slices for each of a plurality of 3D models of objects, wherein the 2D slices are for coordinates along a slicing axis; and characterized in that : for each 2D slice of each 3D model, the processor is to: determine whether the 2D slice is complete or incomplete for additive manufacturing, wherein a 2D slice is determined to be complete when the boundary forms a closed polygon and is determined to be incomplete when it is determined that the boundary has a gap; in response to determining the 2D slices are complete, combine corresponding 2D slices of the plurality of 3D models for each coordinate according to a Boolean operation to generate combined 2D slices printable by an additive manufacturing system, wherein the Boolean operation comprises at least one of AND, OR, and XOR; and. in response to the at least one processor determining that at least one of the 2D slices is incomplete, generating an indication of a defective 3D model. determine two-dimensional slices for each of a plurality of 3D models of objects, wherein the 2D slices are for coordinates along a slicing axis; and characterized in that : for each 2D slice of each 3D model, the processor is to: determine whether the 2D slice is complete or incomplete for additive manufacturing, wherein a 2D slice is determined to be complete when the boundary forms a closed polygon and is determined to be incomplete when it is determined that the boundary has a gap; in response to determining the 2D slices are complete, combine corresponding 2D slices of the plurality of 3D models for each coordinate according to a Boolean operation to generate combined 2D slices printable by an additive manufacturing system, wherein the Boolean operation comprises at least one of AND, OR, and XOR; and. in response to the at least one processor determining that at least one of the 2D slices is incomplete, generating an indication of a defective 3D model. determine whether the 2D slice is complete or incomplete for additive manufacturing, wherein a 2D slice is determined to be complete when the boundary forms a closed polygon and is determined to be incomplete when it is determined that the boundary has a gap; in response to determining the 2D slices are complete, combine corresponding 2D slices of the plurality of 3D models for each coordinate according to a Boolean operation to generate combined 2D slices printable by an additive manufacturing system, wherein the Boolean operation comprises at least one of AND, OR, and XOR; and. in response to the at least one processor determining that at least one of the 2D slices is incomplete, generating an indication of a defective 3D model. <EOS>