Modifying object geometries based on radiant heating distribution

1. A method comprising:

receiving, by a processor, object model data representing a portion of an object defining an initial object geometry, wherein the object is to be generated within a fabrication chamber by an additive manufacturing apparatus by fusing build material using a radiant heater;

determining, by the processor, a non-uniform radiant heating distribution of the additive manufacturing apparatus by using a temperature sensor to monitor a temperature distribution of a heated calibration layer of build material applied within a build chamber of the additive manufacturing apparatus, and by comparing the monitored temperature distribution of the heated calibration layer of the build material to a baseline temperature distribution corresponding to uniform heating by the radiant heater;

determining, by the processor, a first local radiant heating parameter from the non-uniform radiant heating distribution of the additive manufacturing apparatus for a first location in the fabrication chamber, and determining a second local radiant heating parameter from the non-uniform radiant heating distribution for a second location in the fabrication chamber;

eroding or dilating, by the processor, an object model corresponding to the object model data by removing or adding a plurality of sub-volumes of a predetermined size from or to at least one outer surface of the object model;

determining, by the processor, object generation instructions for generating the object in accordance with the eroded or dilated object model, the object generation instructions specifying an amount of print agent to be applied to each of a plurality of locations on a layer of build material; and

causing, by the processor, the additive manufacturing apparatus to physically generate the object in accordance with the determined object generation instructions,

wherein a number of sub-volumes eroded or added proximate the first location in the fabrication chamber when the object is generated within the fabrication chamber in accordance with the eroded or dilated object model is based on the first local radiant heating parameter,

and wherein a number of sub-volumes eroded or added proximate the second location when the object is generated within the fabrication chamber in accordance with the eroded or dilated object model is based on the second local radiant heating parameter.

2. The method of claim 1 , comprising:

analyzing, by the processor, the object model data to determine a first predicted object generation temperature for the first location and a second predicted object generation temperature for the second location,

wherein the first predicted object generation temperature is determined in part based on the first local radiant heating parameter and the second predicted object generation temperature is determined in part based on the second local radiant heating parameter.

3. The method of claim 1 , wherein the numbers of sub-volumes to erode or add proximate the first location and the second location respectively are determined as a function of the respective first and second local radiant heating parameters obtained from the non-uniform radiant heating distribution, and are independent of a predicted temperature distribution in build material owing to object generation.

4. The method of claim 1 , wherein the object model data is defined as a plurality of voxels.

5. A system comprising:

a processor; and

a memory storing instructions executable by the processor to:

receive object model data representing a portion of an object to be generated within a fabrication chamber by an additive manufacturing apparatus using a radiant heater;

determine a non-uniform radiant heating distribution of the additive manufacturing apparatus by using a temperature sensor to monitor a temperature distribution of a heated calibration layer of build material applied within a build chamber of the additive manufacturing apparatus, and by comparing the monitored temperature distribution of the heated calibration layer of the build material to a baseline temperature distribution corresponding to uniform heating by the radiant heater;

determine a first local radiant heating parameter from the non-uniform radiant heating distribution of the additive manufacturing apparatus for a first location in the fabrication chamber, and determine a second local radiant heating parameter from the non-uniform radiant heating distribution for a second location in the fabrication chamber;

erode or dilate an object model corresponding to the object model data by removing or adding a plurality of sub-volumes of a predetermined size from or to at least one outer surface of the object model;

determine object generation instructions for generating the object in accordance with the eroded or dilated object model, the object generation instructions specifying an amount of print agent to be applied to each of a plurality of locations on a layer of build material; and

cause the additive manufacturing apparatus to physically generate the object in accordance with the determined object generation instructions,

wherein a number of sub-volumes eroded or added proximate the first location in the fabrication chamber when the object is generated within the fabrication chamber in accordance with the eroded or dilated object model is based on the first local radiant heating parameter,

and wherein a number of sub-volumes eroded or added proximate the second location when the object is generated within the fabrication chamber in accordance with the eroded or dilated object model is based on the second local radiant heating parameter.

6. The apparatus of claim 5 , wherein the instructions are executable by the processor to further:

analyze the object model data to determine a first predicted object generation temperature for the first location and a second predicted object generation temperature for the second location,

wherein the first predicted object generation temperature is determined in part based on the first local radiant heating parameter and the second predicted object generation temperature is determined in part based on the second local radiant heating parameter.

7. The apparatus of claim 5 , wherein the numbers of sub-volumes to erode or add proximate the first location and the second location respectively are determined as a function of the respective first and second local radiant heating parameters obtained from the non-uniform radiant heating distribution, and are independent of a predicted temperature distribution in build material owing to object generation.

8. The apparatus of claim 5 , wherein the object model data is defined as a plurality voxels.

9. A non-transitory machine readable medium storing instructions which, when executed by a processor, cause the processor to:

receive object model data representing a portion of an object to be generated within a fabrication chamber by an additive manufacturing apparatus using a radiant heater;

determine a non-uniform radiant heating distribution of the additive manufacturing apparatus by using a temperature sensor to monitor a temperature distribution of a heated calibration layer of build material applied within a build chamber of the additive manufacturing apparatus, and by comparing the monitored temperature distribution of the heated calibration layer of the build material to a baseline temperature distribution corresponding to uniform heating by the radiant heater;

determine a first local radiant heating parameter from the non-uniform radiant heating distribution of the additive manufacturing apparatus for a first location in the fabrication chamber, and determine a second local radiant heating parameter from the non-uniform radiant heating distribution for a second location in the fabrication chamber;

erode or dilate an object model corresponding to the object model data by removing or adding a plurality of sub-volumes of a predetermined size from or to at least one outer surface of the object model;

determine object generation instructions for generating the object in accordance with the eroded or dilated object model, the object generation instructions specifying an amount of print agent to be applied to each of a plurality of locations on a layer of build material; and

cause the additive manufacturing apparatus to physically generate the object in accordance with the determined object generation instructions,

wherein a number of sub-volumes eroded or added proximate the first location in the fabrication chamber when the object is generated within the fabrication chamber in accordance with the eroded or dilated object model is based on the first local radiant heating parameter,

and wherein a number of sub-volumes eroded or added proximate the second location when the object is generated within the fabrication chamber in accordance with the eroded or dilated object model is based on the second local radiant heating parameter.

10. The non-transitory machine readable medium of claim 9 , wherein the instructions further cause the processor to:

analyze the object model data to determine a first predicted object generation temperature for the first location and a second predicted object generation temperature for the second location,

wherein the first predicted object generation temperature is determined in part based on the first local radiant heating parameter and the second predicted object generation temperature is determined in part based on the second local radiant heating parameter.

11. The non-transitory machine readable medium of claim 9 , wherein the numbers of sub-volumes to erode or add proximate the first location and the second location respectively are determined as a function of the respective first and second local radiant heating parameters obtained from the non-uniform radiant heating distribution, and are independent of a predicted temperature distribution in build material owing to object generation.