Abstract: An example of a fusing agent includes a tetraphenyldiamine-based dye, alkyldiphenyloxide disulfonate, 1-methyl-2-pyrrolidone, and a balance of water. The fusing agent excludes a strong reducing species. The fusing agent may be incorporated into a three-dimensional printing method or a three-dimensional printing system. In an example of the three-dimensional printing method, a polymeric or polymeric composite build material is applied. The fusing agent is selectively applied on at least a portion of the polymeric or polymeric composite build material. The polymeric or polymeric composite build material is exposed to electromagnetic radiation to fuse the portion of the polymeric or polymeric composite build material in contact with the fusing agent to form a layer.

Abstract: A three-dimensional printing system can include polymeric build material and jettable fluid(s). The polymeric build material can have an average particle size from 20 ?m to 150 ?m, a first melt viscosity, and a melting temperature from 75° C. to 350° C. In one example, the jettable fluid can include water, from 0.1 wt % to 10 wt % of electromagnetic radiation absorber, and from 10 wt % to 35 wt % of an organic solvent plasticizer. Contacting a first portion of a layer of the polymeric build material with the jettable fluid can provide an organic solvent plasticizer loading from 2 wt % to 10 wt % based on the polymeric build material content. The first melt viscosity of the polymeric build material at the first portion can be reduced and the melting temperature of the polymeric build material at the first portion can be decreased by 3° C. to 15° C.

Abstract: According to an example, a three-dimensional (3D) printer may include a first delivery device to selectively deposit first liquid droplets onto a layer of build materials, in which the first liquid has a fusing radiation absorption property. The 3D printer may also include a fusing radiation generator to selectively emit fusing radiation at multiple ranges of wavelengths and at selected locations to selectively fuse the build materials and a controller to tune a range of wavelengths at which the fusing radiation generator is to emit fusing radiation based upon the fusing radiation absorbing property of the deposited first liquid, to determine the selected locations at which the fusing radiation at the tuned range of wavelengths is to be emitted, and to control the fusing radiation generator to selectively emit fusing radiation at the tuned range of wavelengths and onto the selected locations.

Abstract: According to an example, a three-dimensional (3D) printed object may include a body formed of an electrically non-conductive material. In addition, an electrically conductive channel, a sensing device, and a signal emitter may be embedded within the body. The sensing device may be in electrical communication with the electrically conductive channel such that the sensing device is affected by a disruption in a current applied through the electrically conductive channel. In addition, the signal emitter may emit a wireless signal in response to the sensing device being affected by a disruption in the applied current.

Abstract: The present disclosure is drawn to coalescent inks and material sets, such as for 3D printing. In one example, the coalescent ink can include a conjugated polymer, a colorant imparting a visible color to the coalescent ink, and an ink vehicle comprising a high boiling point co-solvent having a boiling point of 250° C. or greater. The high boiling point co-solvent can be present in an amount from about 1 wt % to about 4 wt % with respect to the coalescent ink.

Abstract: The present disclosure is drawn to a particulate build material for three-dimensional printing. The particulate build material can include a plurality of particulates, wherein individual particulates include a particulate core having a photosensitive coating applied to a surface of the particulate core. The particulate core includes a metal, a ceramic, or both a metal and a ceramic. The photosensitive coating includes a polymer having a photosensitive agent suspended or attached therein.

Abstract: A Region Merging image segmentation algorithm based on boundary extraction is disclosed, comprising the steps of calculating a gradient image, extracting a boundary and carrying out initial segmentation and Region Merging, wherein the initial segmentation can be omitted. In the Region Merging process, the ratio of the length of boundary extraction result lies on the adjacent edge between adjacent regions to the length of the adjacent edge is taken as the merging cost, the regions are merged according to the ascending order of the mean gradient value in the region, and a texture difference evaluation mechanism is introduced to remove the error segmentation. The algorithm solves the problems of the other current segmentation algorithms, such as over-segmentation, easy to be influenced by noise and illumination, large in computation and memory consumption, in need of a large number of samples being marked manually and the like.

Abstract: An example system includes a three-dimensional (3D) printer to generate a 3D object and a surface feature formation arrangement to receive the 3D object. The 3D object has at least one surface with a layer of at least partly uncured material. The surface feature formation arrangement includes a controller and a heat source. The controller is to operate the heat source to selectively apply heat to the at least one surface of the 3D object. The heat from the heat source is to transform the at least partly uncured material to form a selected feature on the at least one surface.

Abstract: A three-dimensional printing build material composition includes a polymer particle, and a radiation absorbing additive mixed with the polymer particle. The radiation absorbing additive has a particle size ranging from about 1 ?m to about 100 ?m, and the radiation absorbing additive is to absorb incident radiation having wavelengths ranging from 700 nm to 10 ?m.

Abstract: The present disclosure is drawn material sets, coalescent fluids, and 3-dimensional printing systems. An example material set can include an amorphous polymer powder having an average particle size from 1 micron to 300 microns, and a coalescent fluid including a viscosity reducing agent.

Abstract: In an example implementation, a method of printing a multi-structured three-dimensional (3D) object includes forming a layer of sinterable material. The method includes processing a first portion of the sinterable material using a first set of processing parameters and processing a second portion of the sinterable material using a second set of processing parameters. The processed first and second portions form, respectively, parts of a first and second structure of a multi-structured 3D object.

Abstract: In an embodiment of the invention, an unlocked mobile device is configured to capture images, analyze the images to detect a user's face, and automatically lock the device in response to determining that a user's face does not appear in the images. The camera capturing and face recognition processing may be triggered by the device having detected that it has been motionless for a threshold period of time. In another embodiment, a locked mobile device is configured to capture an initial image using its camera, capture a new image in response to detecting movement of the device, determine that the device moved to a use position, capture a subsequent image in response to determining that the device moved to a use position, analyze the subsequent image to detect a user's face, and unlock the device in response to detecting the user's face. Other embodiments are also described and claimed.

Abstract: A three-dimensional (3D) object printing process-level simulator including, in an example, a layer module for modeling a plurality of layers of a simulated 3D object to be built and a printing device controller to receive a number of simulated values from the layer module to simulate a 3D object printing process and adjust the 3D object printing process based on physical characteristics of a printing device associated with the printing device controller. A cyber-physical three-dimensional (3D) object printing simulator including, in an example, a printing device including a processor to send instructions describing how a simulated 3D object is to be printed and a layers module to simulate heat transfer from a plurality of layers in the 3D object to be printed based at least a density of the plurality of layers.

Abstract: In an example of a three-dimensional (3D) printing method, a polymeric or polymeric composite build material is applied. A fusing agent is selectively applied on at least a portion of the polymeric or polymeric composite build material. The fusing agent includes a discolorable near-infrared absorbing dye, a thiol surfactant, a reducing agent, and a balance of water. Near-infrared radiation is applied to the polymeric or polymeric composite build material at a condition that maintains a temperature of the selectively applied fusing agent below a decomposition temperature of the fusing agent and that allows the discolorable near-infrared absorbing dye to harvest near-infrared radiation energy, in order to fuse the portion of the polymeric or polymeric composite build material in contact with the fusing agent to form a layer and to initiate discoloration of the discolorable near-infrared absorbing dye in the layer.

Abstract: The present disclosure is drawn to material sets for 3D printing and methods of 3D printing. The material set can include a coalescent an organic-soluble near-infrared dye having a peak absorption wavelength from 800 nm to 1400 nm. The coalescent ink can also include water and an organic co-solvent. The material set can also include a particulate polymer formulated to coalesce when contacted by the coalescent ink and irradiated by a near-infrared energy having the peak absorption wavelength.

Abstract: According to an example, an apparatus may include an image capture device, a controller, and a computer readable storage medium. The computer readable storage medium may include instructions that may cause the controller to receive, from the image capture device, an image of a testing agent deposited in a testing pattern onto a layer of build materials, in which the layer of build materials is to form a section of a three-dimensional printed part. The instructions may also cause the controller to determine a condition of the deposited testing pattern in the received image, wherein the determined condition is to be used to determine a quality level of the layer of build materials based upon the determined condition.

Abstract: In an example implementation, a method of printing a multi-structured three-dimensional (3D) object includes forming a layer of sinterable material. The method includes processing a first portion of the sinterable material using first set of processing parameters and processing a second portion of the sinterable material using a second set of processing parameters. The processed first and second portions form, respectively, parts of a first and second structure of a multi-structured 3D object.

Abstract: The present disclosure is drawn to coalescent inks and material sets for 3D printing. The coalescent ink can include an organic-soluble near-infrared dye having a peak absorption wavelength from 800 nm to 1400 nm. The coalescent ink can also include water and an organic co-solvent.

Abstract: Compositions and methods for 3D printing are described herein. In an example, a composition for 3D printing can comprise a build material comprising at least one polymer and at least one first electron donor compound; and a fusing agent comprising (i) a metal bis(dithiolene) complex, (ii) at least one surfactant, at least one second electron donor compound, or combinations thereof, (iii) a polar aprotic solvent, and (iv) water. The at least one first electron donor compound and the at least one second electron donor compound can be the same or different.

Abstract: An example of a fusing agent includes a metal bis(dithiolene) complex, a thiol surfactant, a polar aprotic solvent, and a balance of water. In an example of a method of making the fusing agent, the metal bis(dithiolene) complex is exposed to an aqueous solution including a reducing agent and a thiol surfactant to form a reduced metal bis(dithiolene) complex and to dissolve the reduced metal bis(dithiolene) complex in the aqueous solution. The aqueous solution is incorporated into a vehicle including a water soluble organic solvent and an additive selected from the group consisting of an emulsifier, a surface tension reduction agent, a wetting agent, a scale inhibitor, an anti-deceleration agent, a chelating agent, an antimicrobial agent, and a combination thereof. The fusing agent may be utilized in a three-dimensional printing method and/or incorporated into a three-dimensional printing system.