ADAPTIVE SUPPORTS FOR 3D PRINTING

• US 20150066178A1
• Filed: 08/30/2013
• Published: 03/05/2015
• Est. Priority Date: 08/30/2013
• Status: Active Grant

• Current Assignee: Adobe Inc.
• Original Assignee: Adobe Systems Incorporated (Adobe Inc.)
• Inventors: Stava, Ondrej
• Granted Patent: US 9,688,024 B2
• Time in Patent Office: Days
• US Class Current: 700/98
• CPC Class Codes: B22F 10/31 Calibration of process steps or apparatus settings, e.g. before or during manufacturing
• CPC Class Codes: B22F 10/385 Overhang structures
• CPC Class Codes: B22F 10/47 characterised by structural features
• CPC Class Codes: B22F 10/50 Treatment of workpieces or articles during build-up, e.g. treatments applied to fused layers during build-up
• CPC Class Codes: B22F 10/80 Data acquisition or data processing
• CPC Class Codes: B29C 64/386 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

Methods and systems for defining adaptive support structures for three dimensional (3D) printing are disclosed. An exemplary method detects an area of a 3D model needing support and generates contact points for the area. The method creates a set of virtual supports that extend downward from respective contact points and then identifies connections between the virtual supports in the set, the connections satisfying connection constraints. Next, a virtual support in the set is selected to be a trunk based on comparing connectivity levels of virtual supports in the set, the connectivity level of each of the virtual supports determined by a number of connections between the respective virtual support and other virtual supports. The method then defines a support structure originating from the contact points and including the trunk, at least one virtual support connected to the trunk, and connections between the trunk and the at least one virtual support.

Claims

1. A method comprising:

detecting, by a computing device, at least one area of a three dimensional (3D) model that needs to be supported in a 3D printing of the 3D model;

generating, by the computing device, contact points for the at least one area;

creating a set of virtual supports, each virtual support in the set extending downward from a respective one of the contact points;

identifying connections between the virtual supports in the set, the connections satisfying one or more connection constraints;

selecting a virtual support in the set to be a trunk, the selecting based on comparing connectivity levels of the virtual supports in the set, the connectivity level of each of the virtual supports in the set determined based on a number of connections between the respective virtual support and other virtual supports in the set;

defining a support structure originating from the contact points and extending downward towards a surface, wherein the support structure includes the trunk, at least one virtual support connected to the trunk, and connections between the trunk and the at least one virtual support.

2. The method of claim 1, wherein the selecting comprises selecting a virtual support having a maximal number of connections as the trunk.

3. The method of claim 1, wherein the selecting comprises selecting a virtual support having a number of connections exceeding a threshold as the trunk, the threshold being based on one or more of a predetermined number, a median number of connections for virtual supports in the set, and an average number of connections for virtual supports in the set.

4. The method of claim 1, wherein the creating comprises creating a virtual support for each of the contact points.

5. The method of claim 1, further comprising selecting additional trunks by:

removing the trunk and the at least one virtual support connected to the trunk from the set; and

repeating the identifying, the selecting, and the removing to select the additional trunks until the set is empty.

6. The method of claim 1, further comprising:

removing the trunk and the at least one virtual support connected to the trunk from the set;

repeating the identifying, the selecting, and the removing to select the additional trunks until the set is empty;

receiving a maximum branch level for the support structure, the maximum branch level defining a maximum number of levels of trunks to be included in the support structure;

in response to determining that a trunk in the support structure, if fully extended downward towards the surface, will intersect with the 3D model and that a number of levels of trunks included in the support structure is less than the maximum branch level;

partially extending the trunk downward, with respect to the contact points, so that it does not intersect with the 3D model;

creating a second set of virtual supports, each virtual support in the second set having been selected to be a trunk;

repeating, using the second set, the identifying;

repeating, using the second set, the selecting to select another trunk;

modifying the support structure to include the another trunk, at least one virtual support connected to the another trunk, and connections between the another trunk and the at least one virtual support; and

extending the another trunk downward, with respect to the contact points, towards the surface.

7. The method of claim 1, further comprising:

removing the trunk and the at least one virtual support connected to the trunk from the set;

repeating the identifying, the selecting, and the removing to select the additional trunks until the set is empty;

receiving a maximum branch level for the support structure, the maximum branch level defining a maximum number of levels of trunks to be included in the support structure;

in response to determining that a number of trunks included in the support structure is less than the maximum branch level, creating a second set of virtual supports, each virtual support in the second set having been selected to be a trunk; and

in response to receiving a modification to at least one of the one or more connection constraints;

repeating, using the second set, the identifying;

repeating, using the second set, the selecting to select another trunk;

modifying the support structure to include the another trunk, at least one virtual support connected to the another trunk, and connections between the another trunk and the at least one virtual support; and

extending the another trunk downward, with respect to the contact points, towards the surface.

8. The method of claim 1, further comprising:

removing the trunk and the at least one virtual support connected to the trunk from the set;

repeating the identifying, the selecting, and the removing to select the additional trunks until the set is empty;

in response to determining that a number of levels of trunks in the support structure is less than the maximum branch level;

removing the another trunk and the at least one virtual support connected to the another trunk from the second set;

repeating the identifying, the selecting, the removing, and the modifying until the number of levels of trunks included in the support structure equals the maximum branch level or the second set is empty.

9. The method of claim 1, wherein the detecting comprises:

converting the 3D model into a plurality of two dimensional (2D) layers extending upward from a plane, wherein a first one of the 2D layers is coincident with the plane and each successive one of the 2D layers is above one or more preceding 2D layers;

detecting that a portion of a 2D layer needs to be supported in response to determining that the greater of a distance between the portion and the surface and a distance between the portion and a preceding 2D layer exceeds a maximum distance, the maximum distance being based on properties of an output device and an output material selected to create a 3D object corresponding to the 3D model,

wherein the generating comprises generating the contact points in detected portions of the 2D layers.

10. The method of claim 1, wherein the surface is:

below the contact points; and

one or more of a portion of the 3D model and a plane.

11. The method of claim 1, wherein the surface is below the contact points and coincident with a print pad, a print raft, a scaffold, a printer platform, or a print surface of a 3D printer selected to create a 3D object corresponding to the 3D model.

12. The method of claim 1, wherein the one or more connection constraints prevent identification of connections that are substantially perpendicular to a virtual support or substantially parallel to the surface.

13. The method of claim 1, wherein the one or more connection constraints comprise one or more of:

an intersection constraint restricting connections determined to intersect with the 3D model;

a length constraint limiting connections to a maximum length;

a slope constraint requiring connections to have a minimum slope; and

an angle constraint restricting connections to one or more of;

a maximum angle with respect to a virtual support; and

a minimum angle with respect to the surface.

14. The method of claim 13, wherein the intersection constraint prevents identification of a connection:

intersecting with any portion of the 3D model; and

intersecting with more than two virtual supports.

15. The method of claim 1, further comprising, prior to the detecting, receiving, at the computing device:

the one or more connection constraints; and

parameters for creating a 3D object corresponding to the 3D model using an output device,

wherein the detecting is based at least in part on the one or more connection constraints, the parameters, and properties of the output device.

16. The method of claim 15, wherein:

the properties include one or more of a nozzle diameter range and maximum output dimensions; and

the parameters include one or more of a scaling factor, a layer height, a scaffolding material, and a printing material.

17. The method of claim 15, wherein the detecting comprises detecting, based on the properties and the parameters, the at least one area.

18. A computer readable storage medium having executable instructions stored thereon, that if executed by a processor of a computing device, cause the processor to perform operations, the instructions comprising:

instructions for detecting at least one area of a three dimensional (3D) model that needs to be supported;

instructions for generating contact points for the at least one area; and

instructions for creating a set of virtual supports, each virtual support in the set extending downward from a respective one of the contact points;

instructions for identifying connections between the virtual supports in the set, the connections satisfying one or more connection constraints;

instructions for selecting a virtual support in the set to be a trunk, the selecting based on comparing connectivity levels of the virtual supports in the set, the connectivity level of each of the virtual supports in the set determined based on a number of connections between the respective virtual support and other virtual supports in the set;

instructions for defining a support structure for the 3D model, the support structure including the trunk, virtual supports connected to the trunk, and connections between the trunk and the virtual supports in an adaptive support structure.

19. The computer readable storage medium of claim 18, wherein the instructions for selection further comprise instructions for selecting a virtual support having a maximal number of connections as the trunk.

20. A system comprising:

a computing device including a processor and a memory having instructions stored thereon, that, if executed by the processor, cause the processor to perform operations comprising;

generating contact points for at least one area of a three dimensional (3D) model that needs to be supported;

creating a set of virtual supports, each virtual support in the set extending downward from a respective one of the contact points;

identifying connections between the virtual supports in the set, the connections satisfying one or more connection constraints;

selecting a virtual support in the set to be a trunk, the selecting based on comparing connectivity levels of the virtual supports in the set, the connectivity level of each of the virtual supports in the set determined based on a number of connections between the respective virtual support and other virtual supports in the set;

defining an adaptive support structure for the 3D model, the adaptive support structure including the trunk, one or more virtual supports connected to the trunk, and connections between the trunk and the one or more virtual supports.

21. The system of claim 20, wherein the generating comprises:

converting the 3D model into a plurality of two dimensional (2D) layers;

detecting the least one area of the three dimensional (3D) model that needs to be supported; and

generating the contact points for the at least one area in portions of respective ones of the plurality of 2D layers comprising the at least one area.

22. The system of claim 20, further comprising:

an output device communicatively coupled to the computing device, the output device being configured to create a 3D object corresponding to the 3D model, the operations further comprising;

storing the 3D model and the adaptive support structure in the memory;

receiving properties of the output device and parameters for creating the 3D object at the output device, the properties including one or more of a nozzle diameter range and maximum output dimensions, the parameters including one or more of a scaling factor, a layer height, a scaffolding material, and a printing material.

23. The system of claim 22 wherein:

the output device is a 3D printer; and

the generating comprises distributing the contact points substantially uniformly across the at least one area so that each of the contact points is substantially the same distance from neighboring contact points, the distance being based on properties of the 3D printer.