Segments in virtual build volumes

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.

1 - 15 . (canceled) 
     
     
         16 . An object generation apparatus comprising:
 a build material applicator;   print agent applicators; and   a processor to:
 control the build material applicator to provide a plurality of layers of build material on a print bed; 
 control the print agent applicators to apply print agent onto some of the plurality of layers of build material to generate a core segment having a first color; 
 control the print agent applicators to apply print agent onto some of the plurality of layers of build material to generate an outer peripheral segment having a second color; and 
 control the print agent applicators to apply print agent onto some of the plurality of layers of build material to generate an inner peripheral segment having a third color, wherein the third color is based on the first color and the second color and is to at least partially visually mask the core segment, and wherein the core segment is nested within the inner peripheral segment and the inner peripheral segment is nested within the outer peripheral segment to form an object. 
   
     
     
         17 . The object generation apparatus of  claim 16 , wherein the print agent comprises a colored agent and a fusing agent, the apparatus further comprising:
 a heat source, wherein the processor is to control the heat source to apply radiation on the layers of build material to cause the build material on which the print agent has been applied to fuse together and respectfully form the core segment, the inner peripheral segment, and the outer peripheral segment.   
     
     
         18 . The object generation apparatus of  claim 16 , wherein the processor is to control the print agent applicators to apply a fusing agent and at least. one colorant to generate the outer peripheral segment having the second color, the fusing agent comprising a Caesium Tungsten, Bronze, or a Caesium Tungsten Oxide composition. 
     
     
         19 . The object generation apparatus of  claim 16 , wherein the processor is to control the print agent applicators to apply a fusing agent and at least one colorant to generate the inner peripheral segment having the second color, the fusing agent comprising a Caesium Tungsten, Bronze, or a Caesium Tungsten Oxide composition. 
     
     
         20 . The object generation apparatus of  claim 16 , wherein the processor is to control the print agent applicators to apply a carbon-based fusing agent to generate the core segment. 
     
     
         21 . The object generation apparatus of  claim 16 , wherein the processor is further to:
 control the print agent applicators to apply a fusion inhibiting agent to form a first external peripheral segment that is external to the outer peripheral segment.   
     
     
         22 . The object generation apparatus of  claim 21 , wherein the processor is further to:
 control the print agent applicators to apply at least one colorant, in forming the first external peripheral segment.   
     
     
         23 . The object generation apparatus of  claim 16 , wherein the core segment is encompassed in three dimensions by the inner peripheral segment and wherein the inner peripheral segment is encompassed in three dimensions by the outer peripheral segment. 
     
     
         24 . A method comprising:
 controlling, by a processor, a build material applicator to provide a. plurality of layers of build material on a print bed;   controlling, by the processor, print agent applicators to apply print agent onto some of the plurality of layers of build material to generate a core segment having a first color;   controlling, by the processor, the print agent applicators to apply print agent onto some of the plurality of layers of build material to generate an outer peripheral segment having a second color and   controlling, by the processor, the print agent applicators to apply print agent onto some of the plurality of layers of build material to generate an inner peripheral segment having a third color, wherein the third color is based on the first color and the second color and is to at least partially visually mask the core segment, and wherein the core segment is nested within the inner peripheral segment and the inner peripheral segment is nested within the outer peripheral segment to form an object.   
     
     
         25 . The method of  claim 24 , wherein the print agent comprises a colored agent and a fusing agent, the method further comprising:
 controlling a heat source to apply radiation on the layers of build material to cause the build material on which the print agent has been applied to fuse together and respectfully form the core segment, the inner peripheral segment, and the outer peripheral segment.   
     
     
         26 . The method of  claim 24 , further comprising:
 controlling the print agent applicators to apply the print agent onto the plurality of layers of build material to generate the core segment to be surrounded in three dimensions by the inner peripheral segment and the inner peripheral segment to be surrounded in three dimensions by the outer peripheral segment.   
     
     
         27 . The method of  claim 24 , further comprising:
 controlling the print agent applicators to apply a fusing agent and at least one colorant to generate the outer peripheral segment having the second color, the fusing agent comprising a Caesium Tungsten, Bronze, or a Caesium Tungsten Oxide composition.   
     
     
         28 . A three-din - tensional object comprising:
 a core segment having a first color;   an outer peripheral segment having a second color; and   an inner peripheral segment having a third color, wherein the third color is based on the first color and the second color and is to at least partially visually mask the first color of the core segment, wherein the core segment, the outer peripheral segment, and the inner peripheral segment are formed through selective application of print agents in layers of build material, and wherein the core segment is nested within the inner peripheral segment and the inner peripheral segment is nested within the outer peripheral segment to form an object.   
     
     
         29 . The three-dimensional object of  claim 28 , wherein the core segment is surrounded in three dimensions by the inner peripheral segment and the inner peripheral segment is surrounded in three dimensions by the outer peripheral segment. 
     
     
         30 . The three-dimensional object of  claim 28 , wherein the third color of the inner peripheral segment is to allow for a gradual transition from the first color of the core segment to the second color of the outer peripheral segment while enabling the second color of the outer peripheral segment to closely match an intended color.