Abstract: A computing device comprising a controller is disclosed herein. The controller is to receive a virtual build volume defining an arrangement of a 3D object model to be used by a 3D printer to generate a 3D object; identify a portion of a surface of the to be generated 3D object that is expected to exhibit at least one of a set of surface quality defects; and modify the 3D object model by applying at least one texture pattern to a portion of the 3D object model corresponding to the identified portion, the texture pattern to be selected based on the expected at least one surface quality defect, to cause a 3D geometrical modification of the portion that is to at least partially mask the expected surface quality defect of a 3D object generated using the modified 3D object model.

Abstract: A 3D printer is controlled to apply a print agent at a plurality of predetermined locations in a build chamber of the 3D printer, and energy is applied to heat the build chamber. A thermal image of the build chamber is received. Based on the thermal image, an error in application of the print agent in the build chamber is determined.

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: 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: Methods of treating fused build material in an additive manufacturing system are described. The method includes a first treatment process comprising: depositing unfused build material over the fused build material in a working area of the additive manufacturing system, thereby providing a first build material layer; and supplying energy from a first energy source to the first build material layer to heat but substantially not fuse the unfused build material of the first build material layer. The method also includes a second treatment process comprising: depositing unfused build material over the first build material layer in the working area, thereby providing a second build material layer; and supplying energy from a second energy source to the second build material layer to heat but substantially not fuse the unfused build material of the first and second build material layers.

Abstract: Examples described herein relate to a method of 3D printing. In an example, at least part of a layer of build material is fused. The temperatures of the fused part of the layer are measured at different locations using respective temperature sensors. The temperature sensors are calibrated using the measured temperatures. Heating of additional layers of build material is controlled using the calibrated temperature sensors.

Abstract: Object geometry for three-dimensional printers is described in which a first object to be three-dimensionally printed is identified. Geometry data relating to a geometry of all or part of the first object can be obtained. The geometry data can be compared with a predetermined threshold. A determination can be made as to whether the first object may or may not be adversely affected by a post-processing apparatus that will be used to process the object during a post-processing operation based on the comparison.

Abstract: Object model data modification is described in which object model data defining a first object to be generated by a three-dimensional printer may be obtained. A determination whether the first object is an object that may be adversely affected by a post-processing apparatus during post-processing based on a geometry of the first object to be generated can be made; and if the determination is affirmative, the object model data may be modified by adding a structure to the object model data to create a modified object comprising the first object and the structure, the modified object of a different geometry to the first object so as not to be adversely affected by the post-processing apparatus during the post-processing.

Abstract: A mobile build unit (2) for selectively locating in a build chamber (4) of an additive manufacturing machine (6). The mobile build unit has a build platform (8) to receive build material; and a build unit heater (10) to heat layers of build volume formed on the build platform (8). The build unit heater (10) is movable between a first position in which the build unit heater (10) is stored, and a second position in which the build unit heater (10) is mounted over the build platform (8).

Abstract: An example three-dimensional printer includes a print agent distributor to provide a printing agent to a print bed of powdered build material, a heat source to apply heat over the print bed to form a printed part where printing agent is applied, a heat sensor to measure a temperature of the printed part after heat has been applied, and a processor coupled to the heat sensor. The processor is to determine a target power to be applied to the heat source heat a part to a target temperature in a subsequent printing process. The processor is to determine the target power based on the target temperature, a measured first temperature of a first printed part formed when a first power is applied to the heat source and a measured second temperature of a second printed part formed when a second, different power is applied to the heat source.