Apparatus and methods for modifying a model of an object to enforce compliance with a manufacturing constraint

• US 7,149,596 B2
• Filed: 05/28/2004
• Issued: 12/12/2006
• Est. Priority Date: 01/13/2004
• Status: Active Grant

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: SensAble Technologies, Inc. (3D Systems Corporation)
• Inventors: Shannon, Walter C. III, Berger, Torsten, Payne, Bradley A.
• Primary Examiner(s): Gandhi, Jayprakash N.
• Application Number:
  US10/856,699
• Publication Number:
  US 20050154481A1
• Time in Patent Office: 928 Days
• Field of Search: 700/98, 700/103, 345/419, 345/424, 345/653
• US Class Current: 700/98
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: G06T 19/20 Editing of 3D images, e.g. changing shapes or colours, aligning objects or positioning parts
• CPC Class Codes: G06T 2219/2021 Shape modification

Abstract

The invention provides an apparatus and methods for automatically modifying a computer model of an object to comply with a manufacturing constraint for production of the object. In one embodiment, the invention uses a voxel-based approach to automatically modify an arbitrarily-shaped model at any stage of the design process. For example, a method of the invention automatically modifies a model of a molded object to comply with a draft angle requirement.

Claims

1. A method for automatically modifying a model of a three-dimensional object for compliance with a manufacturing constraint, the method comprising the steps of:

(a) representing a model of an arbitrarily-shaped three-dimensional object with an array of voxel values; and

(b) automatically modifying the array of voxel values according to a manufacturing constraint, wherein the manufacturing constraint comprises a molding constraint.

2. The method of claim 1, wherein the manufacturing constraint comprises a draft angle specification.

3. The method of claim 2, wherein the draft angle specification is user-provided.

4. The method of claim 2, wherein the manufacturing constraint further comprises at least one of a parting curve and a parting direction.

5. The method of claim 4, wherein the manufacturing constraint comprises a plurality of parting curves.

6. The method of claim 4, wherein the manufacturing constraint comprises at least one non-planar parting curve.

7. The method of claim 2, wherein the manufacturing constraint further comprises a mask volume indicating a portion of the model to remain unmodified.

8. The method of claim 1, further comprising at least one of the steps of:

(c) saving the modified array of voxel values to a data storage medium;

(d) displaying the model on a visual display following step (b);

(e) transmitting a copy of the modified array of voxel values over a network;

(f) providing a printed representation of the model following step (b); and

(g) creating a physical three-dimensional representation of the model following step (b).

9. The method of claim 1, further comprising the step of:

(c) graphically rendering the model.

10. The method of claim 9, further comprising the step of:

(d) haptically rendering the model.

11. The method of claim 1, further comprising the step of:

(c) generating a surface mesh corresponding to the modified array of voxel values.

12. The method of claim 11, wherein step (c) comprises using a marching cubes algorithm.

13. The method of claim 1, wherein step (b) is initiated by a user command.

14. The method of claim 1, wherein step (b) comprises a post-processing step.

15. The method of claim 1, wherein step (b) comprises adding virtual material to the model.

16. The method of claim 15, wherein the step of adding virtual material to the model comprises modifying the array of voxel values representing the model to increase a volume encompassed by the model.

17. The method of claim 1, wherein step (b) comprises removing virtual material from the model.

18. The method of claim 17, wherein the step of removing virtual material from the model comprises modifying the array of voxel values representing the model to decrease a volume encompassed by the model.

19. The method of claim 1, wherein step (b) comprises:

(i) adding virtual material to the model; and

(ii) removing virtual material from the model to preserve a given parting curve.

20. The method of claim 1, further comprising the step of automatically determining at least one of a parting curve and a parting direction.

21. The method of claim 1, wherein step (b) comprises modifying voxel values corresponding to each of a plurality of slices of the model.

22. The method of claim 21, wherein the slices are contiguous.

23. The method of claim 22, wherein step (b) comprises sequentially modifying the slices of the model.

24. The method of claim 21, wherein step (b) comprises determining a limit slice for use as a template in modifying voxel values corresponding to a given slice of the model.

25. The method of claim 24, wherein step (b) comprises modifying the limit slice using at least one of:

(i) a previously-modified slice; and

(ii) an offset value.

26. The method of claim 24, wherein the limit slice comprises distance field values indicating distances from an edge of a limit volume, and wherein the distance field values are related to voxel values.

27. The method of claim 1, wherein the array of voxel values comprises one-byte integers.

28. The method of claim 1, wherein the array of voxel values consists essentially of one-byte integers.

29. An apparatus for automatically modifying a model of a three-dimensional object to enforce compliance with a manufacturing constraint, the apparatus comprising:

(a) a memory for storing code that defines a set of instructions; and

(b) a processor adapted to execute the set of instructions to;

(i) represent a model of an arbitrarily-shaped three-dimensional object with an array of voxel values; and

(ii) modify the array of voxel values according to a manufacturing constraint, wherein the manufacturing constraint comprises a molding constraint.

30. The apparatus of claim 29, further comprising:

(c) a graphical user interface device in communication with the processor.

31. The apparatus of claim 30, wherein the graphical user interface device comprises a haptic/graphical user interface device.

32. The apparatus of claim 29, further comprising at least one of:

(c) a data storage medium for storing the modified array of voxel values;

(d) a visual display for displaying the modified model;

(e) a network for transmitting a copy of the modified array of voxel values;

(f) a printer for providing a printed representation of the modified model; and

(g) a three-dimensional printer for creating a physical three-dimensional representation of the modified model.

33. The apparatus of claim 29, wherein the processor is adapted to execute the set of instructions to provide a haptic/graphical user interface element.

34. A method for automatically determining a modification of a model of a three-dimensional object for compliance with a specified draft angle, the method comprising the steps of:

(a) representing a model of an arbitrarily-shaped three-dimensional object with an array of voxel values; and

(b) automatically determining a modification of the array of voxel values for compliance with a draft angle.

35. The method of claim 34, wherein the draft angle is user-specified.

36. The method of claim 34, wherein step (b) comprises determining a modification for compliance with the draft angle and at least one of a parting curve and a parting direction.

37. The method of claim 34, wherein step (b) comprises determining a modification subject to a mask volume, wherein the mask volume indicates a portion of the model to remain unmodified.

38. The method of claim 34, further comprising the step of:

(c) modifying the model according to the automatically determined modification of the array of voxel values.

39. The method of claim 38, further comprising at least one of the steps of:

(d) saving a representation of the modified model to a data storage medium;

(e) displaying the modified model on a visual display;

(f) transmitting a copy of the modified model over a network;

(g) providing a printed representation of the modified model; and

(h) creating a physical three-dimensional representation of the modified model.

40. The method of claim 38, further comprising the step of:

(d) graphically rendering the modified model.

41. The method of claim 40, further comprising the step of:

(e) haptically rendering the modified model.

42. The method of claim 34, wherein step (b) comprises determining a modification of the array of voxel values corresponding to each of a plurality of slices of the model.

43. The method of claim 42, wherein the slices are contiguous.

44. The method of claim 43, wherein step (b) comprises determining a modification of each of the slices of the model in a step-wise manner.

45. The method of claim 42, wherein step (b) comprises determining a limit slice for use as a template in determining a modification of voxel values corresponding to a given slice of the model.

46. The method of claim 45, wherein step (b) comprises modifying the limit slice using an offset value.

47. The method of claim 45, wherein the limit slice comprises distance field values indicating distances from an edge of a limit volume, and wherein the distance field values are related to voxel values.

48. The method of claim 34, wherein the array of voxel values consists essentially of one-byte integers.