Abstract: An example system includes an object and a support frame supporting the object. The support frame constrains movement of the object relative to the support frame, and the support frame includes at least one of a cage or a shackle to non-rigidly constrain movement of at least a part of the object.

Abstract: In example implementations, an apparatus is provided. The apparatus includes a light table, a camera, and a processor communicatively coupled to the light table and the camera. The light table is to emit light through an object on the light table. The camera is to capture an image of the light table. The processor is to receive an image of the light table without the object, receive an image of the light table with the object, and calculate a transmission value for each pixel of the object in the image of the light table with the object, wherein a mechanical property of the object is to be determined based on the transmission value of the object.

Abstract: A three-dimensional printing method can include iteratively applying polymer build material as individual layers; based on a three-dimensional object model, selectively jetting an electromagnetic radiation absorber and a translucency-modulating plasticizer onto individual layers of the polymer build material; and exposing the powder bed to electromagnetic energy to selectively fuse portions of individual layers of the polymer build material together to form a three-dimensional object. The polymer build material can include from about 60 wt % to 100 wt % polymeric particles having an average particle size from about 10 ?m to about 150 ?m and a degree of crystallinity from about 2% to about 60%, to a powder bed. At the locations where the polymer build material includes jetted translucency-modulating plasticizer, the three-dimensional object can exhibit an optical transmittance from about 5% to about 80%.

Abstract: In an example, a method includes receiving, at a processor, a plurality of property parameter sets representing attainable property combinations in additive manufacturing and being associated with print material description. A constraint of a first property of the property parameter sets may also be received and a hull of a property mapping resource for use in determining additive manufacturing instructions for generating an object in which the first property meets the received constraint may be determined.

Abstract: A three-dimensional printing system includes a controller to instruct a fusing agent distributor to selectively apply a fusing agent to a first region of a layer of build material. The controller also determines a subset of voxels in the layer of build material to provide an opacifying agent based on an opacity value of an opacified region of an object to be generated and instructs an opacifying agent distributor to apply the opacifying agent to the determined subset of voxels.

Abstract: According to an example, an apparatus may include a processor and a memory on which is stored instructions that are to cause the processor to identify features for a three-dimensional (3D) indicator object to be fabricated by a 3D fabricating device, in which the identified features define a shape and a pattern of colors for the 3D indicator object. The instructions may also cause the processor to instruct the 3D fabricating device to fabricate the 3D indicator object to have the identified features, in which the 3D indicator object has a shape having a plurality of surfaces on which a plurality of colors are arranged in a certain pattern as defined by the identified features, and in which each of the plurality of surfaces has the same certain pattern of the plurality of colors and determine properties of the fabricated 3D indicator object.

Abstract: In example implementations, an apparatus is provided. The apparatus includes a light table, a camera, and a processor. The light table is to hold an object. The camera is to capture images. The light table is positioned within a field of view of the camera. The processor is communicatively coupled to the camera to receive the images. The processor is to analyze the images to calculate an imaged transmission percentage at a plurality of different locations of the object based on a correlation function of the camera used to determine an amount of print agents to be dispense by a three dimensional printer to print the object.

Abstract: In an example, a method includes receiving, at a processor, a first matrix comprising a set of print coverage vectors, each print coverage vector specifying print materials for object generation using additive manufacturing and a second matrix comprising a corresponding set of properties for objects generated using the print coverage vectors. The method may further include determining, by the processor, a solution to an objective function relating the first and second matrices.

Abstract: In an example, a method includes receiving, at a processor, a plurality of property parameter sets representing attainable property combinations in additive manufacturing and being associated with print material description. A constraint of a first property of the property parameter sets may also be received and a hull of a property mapping resource for use in determining additive manufacturing instructions for generating an object in which the first property meets the received constraint may be determined.

Abstract: In one example in accordance with the present disclosure a three-dimensional illumination chart is described. The chart includes a substrate divided into a number of portions. Each portion includes a raised relief pattern disposed thereon having a relief angle relative to a reference line. Each relief angle of the raised relief patterns of the number of portions is different from other relief angles of other raised relief patterns of other of the number of portions.

Abstract: According to an example, an apparatus may include a processor and a memory on which is stored instructions that are to cause the processor to identify features for a three-dimensional (3D) indicator object to be fabricated by a 3D fabricating device, in which the identified features define a shape and a pattern of colors for the 3D indicator object. The instructions may also cause the processor to instruct the 3D fabricating device to fabricate the 3D indicator object to have the identified features, in which the 3D indicator object has a shape having a plurality of surfaces on which a plurality of colors are arranged in a certain pattern as defined by the identified features, and in which each of the plurality of surfaces has the same certain pattern of the plurality of colors and determine properties of the fabricated 3D indicator object.

Abstract: An example system includes an object and a support frame supporting the object. The support frame constrains movement of the object relative to the support frame, and the support frame includes at least one of a cage or a shackle to non-rigidly constrain movement of at least a part of the object.

Abstract: In an example, a processing apparatus includes an interface to receive data representing a three-dimensional object. The data includes an object description comprising object property data. The processing apparatus comprises a mapping module to map the object description to an object generation description which includes at least one print material instruction associated with a predetermined combination of print materials from a set of print materials. The mapping module includes a plurality of mapping resources and each mapping resource associates combinations of print materials from the set of print materials with values of at least one object property. At least one object property of one mapping resource is different to at least one object property of another mapping resource. The processing apparatus also includes a selection module to select, for at least part of the object, one of the plurality of mapping resources to carry out mapping of the object description.

Abstract: In one example in accordance with the present disclosure a three-dimensional illumination chart is described. The chart includes a substrate divided into a number of portions. Each portion includes a raised relief pattern disposed thereon having a relief angle relative to a reference line. Each relief angle of the raised relief patterns of the number of portions is different from other relief angles of other raised relief patterns of other of the number of portions.

Abstract: A system including a memory to store instructions and initial color representations and a processor to execute the instructions in the memory to reference a database having a set of lexical color classifiers, transform each of at least a pair of initial color representations to color values associated with the set of lexical color classifiers, and generate a relative similarity measure related to the at least a pair of initial color representations based on the color values associated with the set of lexical color classifiers.

Abstract: A system including a memory to store instructions and initial color representations and a processor to execute the instructions in the memory to reference a database having a set of lexical color classifiers, transform each of at least a pair of initial color representations to color values associated with the set of lexical color classifiers, and generate a relative similarity measure related to the at least a pair of initial color representations based on the color values associated with the set of lexical color classifiers.

Abstract: The present disclosure related to acquisition of color calibration charts. In at least some examples herein, an image of a calibration color chart is processed. A lighting condition of the color calibration chart may be automatically determined.

Abstract: The present disclosure related to acquisition of color calibration charts. In at least some examples herein, an image of a calibration color chart is processed. A lighting condition of the color calibration chart may be automatically determined.

Abstract: The present disclosure related to acquisition of color calibration charts. In at least some examples herein, an image of a calibration color chart is processed. A lighting condition of the color calibration chart may be automatically determined.

Abstract: Color chart characterization and techniques related therewith are described herein. In an example, an image including a reproduction of a color chart may be received by a computing system. Data associated with the color chart may be received. The data is encoded in an encoding element located in a substrate including the color chart. The color chart may be automatically characterized based on the received data.