Abstract: An apparatus comprises a processor and a machine-readable storage medium storing machine-readable instructions executable by the processor. The machine-readable instructions comprise instructions to cause the processor to create 3D print data including data defining one or more objects to be printed in a build chamber of a 3D printer and data defining, in addition to the one or more objects, a shield to be printed to shield the one or more printed objects in the build chamber to reduce heat dissipation to an outside of the build chamber. The shield is designed depending on a thermal behavior of the build chamber and/or depending on a thermal behavior of the one or more objects to be printed.

Abstract: In an example, a method includes receiving, by at least one processor, object model data, the object model data describing at least part of an object to be generated in additive manufacturing. Pattern data is also received, wherein the pattern data describes a pattern of variable opacity intended to be formed internally to the object. Object generation instructions for generating an intermediate layer of the object comprising the pattern of variable opacity may be determined by at least one processor.

Abstract: In one example a method of generating a three-dimensional object in a 3D printing system using a fusing agent of a first colour and a build material having a second colour different from the first colour, and a detailing agent, comprises obtaining object model data describing an object to be generated, and determining a first portion of the object to be generated to have the second colour. The method comprises determining object generation instructions to generate the object by defining a gap region of a layer of build material that is to correspond to the first portion of the object to have the second colour on which no agents are to be applied, a band of detailing agent on a layer of build material immediately adjacent to the gap region to define an outer limit of the gap region and therefore a boundary of the first portion of the object, and a fusing agent region on a layer of build material adjacent to the gap region on which fusing agent is to be applied.

Abstract: A system includes a controller to receive data corresponding to an object or slices of the object to be generated by a 3D printer, wherein the 3D printer includes an array of printhead nozzles to selectively eject a print agent on a layer of build material in a build chamber having a build chamber wall, the array of printhead nozzles spanning substantially the full width of the build chamber and moveable along a length of the build chamber. The controller to generate first print data used to generate layers of the object based on the received object data, and to generate second print data used to generate layers of a sacrificial barrier located between the object and the build chamber wall, the second print data is generated such that different parts of the sacrificial barrier are generated using a different plurality of nozzles of the array of printhead nozzles.

Abstract: An apparatus is described which comprise a material mixer to provide build material from at least a first build material supply and a second build material supply to a build unit of a 3D printer. The first build material and the second build material are mixed according to a mixing ratio. The apparatus further comprises a processor to determine the mixing ratio based on inputs indicating at least print job characteristics and material constraints.

Abstract: Example additive manufacturing apparatus is disclosed comprising a print agent distributor, and a controller to define print data for additive manufacture of a solid part of an object to be manufactured, wherein the print data is to cause a print agent distributor to apply fusing agent to portions of a layer of build material, wherein the print data is to cause a print agent distributor to apply fusing agent to portions of a layer of build material at a concentration based on a distance of each portion of build material from an edge of the object such that the print data causes the print agent distributor to apply fusing agent to portions of a layer of build material having a first range of distances at a first range of concentrations, apply fusing agent to portions of build material having a second range of distances at a second range of concentrations lower than the first range of concentrations, apply fusing agent to portions of build material having a third range of distances at the first range of concent

Abstract: In certain examples, a method comprises determining a fusing area density distribution of a build layer from build data relating to a build layer of a three-dimensional model to be printed by an additive manufacturing system. The method comprises, in response to a determination that a region of the build layer has a fusing area density outside of a fusing area density tolerance window, modifying the build layer to define a build layer in which the region has a fusing area density that is within the fusing area density tolerance window.

Abstract: An example method to control a 3D printing system is described. In that example a print agent is selectively deposited onto a portion of a build material layer and based on a reflectance of the portion of the build material layer, an amount of energy to be applied to the portion is determined.

Abstract: In one example, an apparatus comprising a controller to instruct a build platform to support a plurality of layers of build material in a build zone, wherein the build platform is moveable during a build of a three-dimensional object to change the size of the build zone, wherein the controller is to determine respective displacements of the build platform to successively receive each of the plurality of layers of build material in the build zone during the build, wherein at least one of the respective displacements is based on data determined from a three-dimensional object obtained in a previous build.

Abstract: A method is disclosed. The method may comprise obtaining, using a processor, design data representing an object to be generated in a fabrication chamber of an additive manufacturing apparatus. The method may further comprise determining, based on the design data, that a part of the object is to be generated within a predefined portion of the fabrication chamber. The method may further comprise responsive to said determining, generating, using a processor, data representing an ancillary element to be generated in the predefined portion between the part of the object and a wall of the fabrication chamber. An apparatus and a machine-readable medium are also disclosed.

Abstract: A method of configuring an additive manufacturing system. The method comprises configuring the additive manufacturing system with a first value of an operation parameter associated with the additive manufacturing system and, with the additive manufacturing system configured with the first value of the operation parameter, forming, in a build chamber, a first object The additive manufacturing system is subsequently configured with a second value of the operation parameter and, with the additive manufacturing system configured with the second value of the operation parameter, a second object is formed in the build chamber, subsequently to forming the first object. The method further includes receiving a signal indicative of which of the first value or the second value the operation parameter is to be configured with for subsequent operation of the additive manufacturing system.

Abstract: Certain examples relate to altering at least one control parameter of a printing process in an additive manufacturing system. In these examples following a change in operative state of at least one energy source at least one control parameter of a printing process is altered. An energy source is a device configured to apply energy to build material to facilitate the solidification of said build material. Control parameters determine the way a printing process is carried out. In some of these examples control parameters may be the irradiance of an energy source or the way in which the energy source moves over the build material to apply energy to the build material.

Abstract: An example of an apparatus is disclosed. The example disclosed herein comprises a sensor and a controller. The sensor, coupled to the controller, is to measure a temperature from a three-dimensional printing build material layer. The controller is to control an energy source to apply energy to the build material layer. The controller is further to measure a temperature from the build material layer using the sensor. The controller is also to determine a build material quality level comprising at least one of a first quality level, a second quality level, and a third quality level based on the measured temperature.

Abstract: A method and system for classifying a plurality of three-dimensional objects to be formed by an additive manufacturing system into a plurality of groups, each associated with a different respective value of an operation parameter associated with the additive manufacturing system. First and second portions of a build volume of the additive manufacturing system are assigned to first and second groups of the plurality of groups, respectively. With the additive manufacturing system configured with a first value of the operation parameter, the additive manufacturing system is used to form, within the first portion of the build volume, a first object of the first group. Subsequently, the additive manufacturing system is configured with a second value of the operation parameter and used to form, within the second portion of the build volume, a second object of the second group.

Abstract: In some examples, an agent distributor may be to selectively deliver agent through nozzles of the agent distributor to portions of layers of build material in patterns derived from agent delivery control data representing slices of a three-dimensional object such that the portions are to solidify to form the slices in accordance with the patterns. While generating the three-dimensional object, the agent distributor may be primed such that a particle of the build material is removed from the agent distributor through at least one of the nozzles.

Abstract: In some examples, an agent distributor may be to selectively deliver agent through nozzles of the agent distributor to portions of layers of build material in patterns derived from agent delivery control data representing slices of a three-dimensional object such that the portions are to solidify to form the slices in accordance with the patterns. While generating the three-dimensional object, the agent distributor may be primed such that a particle of the build material is removed from the agent distributor through at least one of the nozzles.