Abstract: In an example implementation, a method of compensating for dimensional variation in 3D printing includes receiving a 3D object model that represents a 3D part to be printed. The method also includes receiving a build material type and a position for printing the 3D part within a build volume. The method includes determining from the position, target subvolumes of the build volume into which the 3D part is to be printed, retrieving a dimensional compensation factor associated with each target subvolume, and then applying each dimensional compensation factor to the 3D object model to scale the 3D part according to the position of the 3D part within the build volume.

Abstract: In an example a method includes identifying, by a processor, in a data model of at least a portion of a three-dimensional object, an object property associated with a location in the three-dimensional object. A data model of a virtual build volume comprising at least a portion of the three-dimensional object may be generated in which an association with an object property is dispersed beyond the location.

Abstract: In one example, a fusing system for an additive manufacturing machine includes a fusing lamp to heat build material in the work area, a heat sensor to measure a heat output of the fusing lamp, and a controller operatively connected to the fusing lamp and to the heat sensor to adjust the heat output of the fusing lamp to the work area based on a heat output measured by the heat sensor.

Abstract: In an example, a method includes receiving, at a processor, a data model of an object to be generated in additive manufacturing. A virtual build volume comprising a representation of at least a portion of the object may be segmented into a plurality of nested segments comprising a core segment and a peripheral segment. Segmenting the virtual build volume may comprise determining a dimension of the peripheral segment based on at least one of a geometry of the object and an intended object property.

Abstract: In an example implementation, a method of processing a 3D object model includes receiving render data of a 2D slice of a 3D object model and generating distance values indicating how far away voxels in the 2D slice are from a nearest edge of the 3D object model. The method also includes detecting a feature of the 3D object model from the distance values, and generating modified render data to be subsequently used in a 3D printing system to produce the feature in a 3D part.

Abstract: In an example implementation, a method of printing a three-dimensional (3D) object includes scanning a print bar in a first direction over a build platform of a 3D printer to deposit a liquid agent onto a layer of build powder. The print bar is then indexed in a second direction substantially orthogonal to the first direction before scanning the print bar back over the build platform in a third direction opposite the first direction to deposit additional liquid agent onto the layer of build powder.

Abstract: According to examples, an apparatus may include a processor and a memory on which are stored machine-readable instructions that when executed by the processor, may cause the processor to access data corresponding to a 3D object model, in which the data may identify a label placeholder on the 3D object model. The processor may also access fabrication information pertaining to a 3D object to be fabricated based on the data, generate a defined label based on the accessed fabrication information, and may insert the defined label at the label placeholder on the 3D object model, such that the 3D object may be fabricated with the defined label positioned at a location on the 3D object corresponding to the label placeholder on the 3D object model.

Abstract: A control system for a three-dimensional printer includes an energy component interface, an agent depositing component interface, and control logic. The control logic controls the operation of an energy component through the energy component interface and an agent depositing component through the agent depositing component, in forming an output object that is specified in a print job. Additionally, in some examples, the control logic can implement a plurality of modes. Each mode, when selected modulate one or more operational parameters of a least one of the energy component or agent depositing component.

Abstract: In some examples, with respect to feature protection for three-dimensional printing, a three-dimensional model of a three-dimensional object to be printed may be ascertained. A determination may be made as to whether a configuration of a three-dimensional model feature of the three-dimensional model matches a removable feature configuration from a set of removable feature configurations. Based on a determination that the configuration of the three-dimensional model feature of the three-dimensional model matches the removable feature configuration from the set of removable feature configurations, the three-dimensional model feature may be removed from the three-dimensional model to generate a modified three-dimensional model.

Abstract: In an example, a method includes segmenting, using a processor, a virtual volume comprising a representation of at least a part of an object to be generated in additive manufacturing. The virtual volume may be segmented into a plurality of segments and the object may be intended to have a first color. Additive manufacturing control instructions may be determined for the segments. The additive manufacturing control instructions may comprise instructions for distributing the print agent composition and the additive manufacturing control instructions for each segment may be determined based on the thermal properties of a print agent composition intended to provide the first color to compensate for variations in object dimensions associated with the thermal properties.

Abstract: In an example, a virtual build volume comprising a representation of at least a part of an object to be generated in additive manufacturing is segmented into a plurality of nested segments comprising a core segment, an inner peripheral segment and an outer peripheral segment. Additive manufacturing control instructions may be generated for the nested segments. The control instructions for the core segment may provide a first region of the object corresponding to the core segment and having a first color. The control instructions for the outer peripheral segment may provide a second color for a second region of the object corresponding to the outer peripheral segment. The control instructions for the inner peripheral segment may provide a third color for a third region of the object corresponding to the inner peripheral segment, wherein a color of the third region is determined so as to at least partially visually mask the first region.

Abstract: According to examples, an apparatus may include a processor and a memory on which are stored machine-readable instructions that when executed by the processor, may cause the processor to identify a property of a portion of a three-dimensional (3D) part to be fabricated and determine, based on the identified property, a thermal value associated with the portion. The instructions may also cause the processor to, based on the determined thermal value, determine a first agent composition to be used to fabricate the portion and determine a second agent composition to be used to fabricate a section external and adjacent to the portion, in which the first agent composition and the second agent composition may be determined to cause the portion and the external section to be fabricated to have the identified property while maintaining the external section separate from the portion.

Abstract: According to examples, an apparatus may include a processor and a memory on which are stored machine-readable instructions that when executed by the processor, may cause the processor access a thermal simulation of a three-dimensional (3D) model, the thermal simulation identifying thermal values simulated to occur across the 3D model during fabrication of a 3D part corresponding to the 3D model. The instructions may also cause the processor to determine a modification to be applied to first thermal values corresponding to a first section of the 3D model, in which the modification may increase accuracy of the first thermal values in the thermal simulation and to apply the determined modification to the first thermal values to generate a modified thermal simulation of the 3D model.

Abstract: In an example, a method includes forming a layer of build material, processing a first portion of the build material by distributing a print agent using a first distribution pattern, the first distribution pattern having a first print agent dispersion characteristic and processing a second portion of the build material by distributing a print agent using a second distribution pattern, the second distribution pattern having a second print agent dispersion characteristic. The method may further include heating the build material by exposing the layer of build material to radiation so as to cause fusing of the first and second portion.

Abstract: One example of a method includes receiving a three-dimensional (3D) model of an object to be 3D printed and voxelizing the 3D model to define a plurality of voxel layers. Each voxel layer defines a plurality of voxel rows including an initial voxel row. The method includes for each voxel layer: exclusively oring (XORing) a key voxel row with the Initial voxel row to provide an initial delta row; and for each voxel row from the voxel row following the initial voxel row to a further voxel row of the plurality of voxel rows, XORing each voxel row with the previous voxel row to provide a delta row for each voxel row.

Abstract: According to examples, an apparatus may include a processor and a memory on which are stored machine-readable instructions that when executed by the processor, may cause the processor to identify a first orientation of a first surface portion of a three-dimensional (3D) model. The instructions may also cause the processor to, based on the identified first orientation of the first surface portion, determine a first thickness of a first section of a first geological region of the 3D model, the first section being adjacent to the first surface portion, in which a plurality of different orientations of 3D model surface portions are correlated to a plurality of different thicknesses. The instructions may further cause the processor to define the first section of the first geological region to have the determined first thickness.

Abstract: In an example implementation, a method of printing a three-dimensional (3D) object includes scanning a print bar in a first direction over a build platform of a 3D printer to deposit a liquid agent onto a layer of build powder. The print bar is then indexed in a second direction substantially orthogonal to the first direction before scanning the print bar back over the build platform in a third direction opposite the first direction to deposit additional liquid agent onto the layer of build powder.

Abstract: A control system for a three-dimensional printer includes an energy component interface, an agent depositing component interface, and control logic. The control logic controls the operation of an energy component through the energy component interface and an agent depositing component through the agent depositing component, in forming an output object that is specified in a print job. Additionally, in some examples, the control logic can implement a plurality of modes. Each mode, when selected modulate one or more operational parameters of a least one of the energy component or agent depositing component.

Abstract: In an example, a virtual build volume comprising a representation of at least a part of an object to be generated in additive manufacturing is segmented into a plurality of nested segments comprising a core segment, an inner peripheral segment and an outer peripheral segment. Additive manufacturing control instructions may be generated for the nested segments. The control instructions for the core segment may provide a first region of the object corresponding to the core segment and having a first color. The control instructions for the outer peripheral segment may provide a second color for a second region of the object corresponding to the outer peripheral segment. The control instructions for the inner peripheral segment may provide a third color for a third region of the object corresponding to the inner peripheral segment, wherein a color of the third region is determined so as to at least partially visually mask the first region.

Abstract: In an example, a method includes acquiring, at a processor, object model data for an object to be generated in additive manufacturing, the object model data representing the object as a plurality of polygons. A virtual object space enclosing the object may be inspected from a plurality of discrete source points in a plane. For each of a plurality of distances from each source point, it may be determined if a polygon face is encountered, and if so, a counter may be set based on whether the polygon face is oriented towards the source point or away from the source point. Based on a content of the counter, it may be determined if a volume enclosed between two distances from a source point is a volume of the object.