Abstract: In some examples, a system receives a first representation of structures to be combined for building a three-dimensional (3D) object by an additive manufacturing machine; and generates, based on the first representation, a second representation comprising voxels that represent the 3D object, the generation of the second representation comprising an evaluation of Boolean operations with respect to voxels in a voxel space to produce the second representation.

Abstract: In an example, mesh model data representing at least a portion of a print job to be generated by an additive manufacturing apparatus by solidifying build material is received at a processor. Using a processor and based on the mesh model data, it is validated whether the three-dimensional print job described by the mesh model data conforms with at least one of material-dependent shape constraints and apparatus-dependent shape constraints of the additive manufacturing apparatus. If the result of the validation is positive, the mesh model data is rendered, using a processor for manufacturing the three-dimensional print job by an additive manufacturing apparatus. If the result of the validation is negative, a predetermined action is performed.

Abstract: In an example, a method includes receiving, at a processor, an indication of a volume of a fabrication chamber and determining a characteristic of a build material for use in fabricating an object within the fabrication chamber. Based on the build material characteristic, a virtual object volume within the fabrication chamber may be determined, wherein the virtual object volume provides a virtual boundary within which to position virtual objects representing objects to be generated in the fabrication chamber.

Abstract: In an example, a method comprises dispensing a first print agent onto a layer of build material in an additive manufacturing apparatus. The additive manufacturing apparatus may have a first print bar and a second print bar. The method may comprise determining a pattern of a first print agent to be applied to a layer of build material, dispensing a first portion of the determined pattern of the first print agent onto the layer of build material from the first print bar and dispensing a second portion of the determined pattern onto the layer of build material from the second print bar.

Abstract: A method is described in which model data describing a three-dimensional object is received. A first offset is applied to a surface of the object, the first offset being applied to the model data. The model data is converted to voxel data, and a second offset is applied to the surface of the object, the second offset being applied to the voxel data.

Abstract: In an example a method comprises receiving at a processor, a digital model representing an object to be produced by additive manufacturing. The method may comprise receiving, at the processor, a selected location on a surface of the object, where a label is to be formed. The method may further comprise defining a label displacement map associated with the selected location, applying the label displacement map to the digital model, and rendering the digital model including the label displacement map into voxels for additive manufacturing.

Abstract: In an example, an apparatus comprises processing circuitry, the processing circuitry comprising: memory, to store a two-dimensional pixel representation of a layer of an object to be made in an additive manufacturing process and pixel information, the pixel information specifying pixels representing a surface of the object and colour for the pixels representing the surface; and an image processor, to generate a downscaled representation of the layer and to process the downscaled representation to propagate colour from pixels representing the surface of the object in the downscaled representation to neighbouring pixels representing an interior of the object in the downscaled representation.

Abstract: In an example, a method includes receiving, at a processor, object model data representing an object that is to be generated by an additive manufacturing apparatus by fusing build material within a fabrication chamber wherein a dimensional compensation has been applied to the object model data based on an expected object placement position. The method may comprise receiving, from the additive manufacturing apparatus, an indication of an object generation placement position within a fabrication chamber where the object is to be generated and comparing, by the processor, the expected object placement position with the object generation placement position. If the expected object placement position matches the object generation placement position, the method may comprise determining, by the processor, that the dimensional compensation is valid and otherwise determining, by the processor, that the dimensional compensation is invalid.

Abstract: According to an example, a method of processing a print job in an additive manufacturing system comprises: applying a geometrical calibration to the print job to obtain a calibrated job; determining a height of a set of print job powder layers to be formed to generate the objects based on the calibrated print job; determining a height of a set of warming powder layers to be formed prior to the set of print job powder layers; determining an ideal height of a set of annealing powder layers to be formed after to the set of print job powder layers; and determining if the combined height of the sets of layers exceeds the maximum available height.

Abstract: In an example, a method comprises receiving, at a processor, a digital model representing an object to be produced by additive manufacturing. The method may comprise receiving, at the processor, an indication that a first selected region of a surface of the object is to have a first coating applied after printing. The method may further comprise applying a first predefined surface roughness pattern to the first selected region of the surface of the digital model.

Abstract: Examples of methods for determining displacement maps are described herein. In some examples of the methods, a method includes determining a displacement map for a three-dimensional (3D) object model based on a compensated point cloud. In some examples, the method includes assembling the displacement map on the 3D object model for 3D manufacturing.

Abstract: In an example, a method includes acquiring, by a processor and for a set of locations in a fabrication chamber for additive manufacturing, data identifying a first subset of locations associated with a first level of variability in deformations in object generation and a second subset of locations associated with a second, greater, level of variability in deformations object generation. A geometrical compensation model may be derived to compensate for anticipated deformations in object generation by a first additive manufacturing apparatus. The geometrical compensation model may comprise geometrical transformations to apply to object model data representing at least a portion of an object, wherein each geometrical transformation is associated with a location of the set of locations.

Abstract: A method comprises: obtaining object model data defining an object or objects to be built by a three-dimensional printing apparatus; determining an effect of carrying out a post-build process on the object or objects, wherein the determining uses the object model data and a computer-implemented evaluation of the post-build process and is carried out prior to building the object or objects, identify portions of the object or objects that would not be processable by the cleaning process; and outputting an indication of non-processability of portions of the object or objects are determined not to be processable by the post-build process.

Abstract: In an example implementation, a method of submitting 3D object models to a 3D printing system includes receiving a digital object model as a triangle mesh, and integerizing floating-point X, Y, Z, coordinate values of triangle vertices that define triangles of the triangle mesh. The method includes storing the digital object model in a 3D print file as an integerized triangle mesh comprising the integerized X, Y, Z, coordinate values, and then submitting the 3D print file with the integerized triangle mesh to the 3D printing system to produce the 3D object.

Abstract: In an example, a method includes receiving, at a processor, an object model describing a geometry of a three-dimensional object, and determining a transformed data model describing a volume containing a modified version of the three-dimensional object as a plurality of categorised contiguous, non-overlapping sub-volumes, wherein the modified version of the three-dimensional object includes a surface offset. Determining the transformed data model may comprises categorising the sub-volumes by defining a first region by determining an area swept by an offset operator when the offset operator is swept around a boundary of the sub-volume and defining a second region, interior to the first region, and indicative of the closest approach of the offset operator to the sub-volume when the offset operator is swept around the boundary. Intersections between a surface of the object model and at least one of the first and second region may be determined.

Abstract: In an example a method includes receiving, at processing circuitry, beam lattice data modelling at least part of a three-dimensional object to be generated using additive manufacturing as a beam lattice. A volumetric data model may be determined from the beam lattice data. Determining the volumetric data model may comprise dividing a volume containing the beam lattice data into sub-volumes and categorising the sub-volumes into (I) interior sub-volumes, which are wholly within a beam of the beam lattice; (ii) exterior sub-volumes which are wholly outside the beams of the beam lattice; and (ii) boundary sub-volumes which partially coincide with a beam of the beam lattice. The method may further comprise subdividing boundary sub-volumes and categorising the subdivided sub-volumes until a threshold volume size of boundary sub-volume is reached.

Abstract: In some examples, a system receives a first representation of structures to be combined for building a three-dimensional (3D) object by an additive manufacturing machine; and generates, based on the first representation, a second representation comprising voxels that represent the 3D object, the generation of the second representation comprising an evaluation of Boolean operations with respect to voxels in a voxel space to produce the second representation.

Abstract: According to examples, machine-readable instructions may cause a processor to obtain a 3D mesh model of a part and to obtain a displacement map that defines amounts of displacements to be applied to various points in the 3D mesh model, in which the displacement map is at a first resolution. The processor may also generate a lower resolution version of the displacement map, in which the lower resolution is lower than the first resolution. The processor may further apply the lower resolution version of the displacement map on the 3D mesh model to generate an updated 3D mesh model.

Abstract: A method (2 analyses (4) a layer of a three-dimensional print job wherein the value of a parameter relating to the processing time of the layer is determined. The method (2) determines (6) whether the layer of the three-dimensional print job is to be printed in a three-dimensional printer. This determination is based on the value of the parameter relating to processing time.

Abstract: According to examples, a processor may dilate a first digital model of a first 3D part a predefined amount and a second digital model of a second 3D part the predefined amount, in which the first 3D part and the second 3D part are to be fabricated together in an assembly to have a functional relationship with respect to each other, and in which the first digital model and the second digital model are spaced from each other in a manner that corresponds to a spacing of the first 3D part and the second 3D part in the assembly. The processor may determine a spatial relationship between the dilated first digital model and the dilated second digital model and may determine, based on the determined spatial relationship, whether the assembly of the first 3D part and the second 3D part is predicted to function properly when the assembly is fabricated.