Method of and apparatus for production of three-dimensional objects by stereolithography with reduced curl

• US 5,104,592 A
• Filed: 04/17/1989
• Issued: 04/14/1992
• Est. Priority Date: 04/18/1988
• Status: Expired due to Term

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Inventors: Smalley, Dennis R., Hull, Charles W., Lewis, Charles W., Spence, Stuart T., Freed, Raymond S., Vinson, Wayne A.
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US07/339,246
• Time in Patent Office: 1,093 Days
• Field of Search: 264/22, 264/40.1, 264/236, 264/255, 264/298, 264/308, 264/347, 425/135, 425/174, 425/174.4, 156/64, 156/273.3, 156/273.5, 156/275.5, 156/307.1, 156/378, 156/379.6, 156/272.8, 427/8, 427/53.1, 427/54.1, 427/430.1, 118/402, 118/620, 118/713, 118/423, 118/429, 364/468, 364/474.05, 364/474.24, 364/476, 364/474.08, 364/521, 364/522, 365/107, 365/119, 365/120, 365/127, 365/106, 365/126, 250/432 R, 250/492.1
• US Class Current: 264/401
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• 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 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B44B 1/006 using computer control means
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/70416 2.5D lithography

Abstract

An improved sterolithography system for generating a three-dimensional object from object defining information, the information defining the object being structurally specified to reduce curl, stress and distortion in the ultimately formed object is described. A stereolithographic distortion known as curl is reduced by the system, and several techniques to eliminate or reduce curl are utilized by the system, including dashed line, bent line, secondary structure, rivets, and multi-pass techniques.

Claims

1. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming and adhering said second portion to said first portion upon more than two exposures to the synergistic stimulation, said more than two exposures including a first exposure, whereupon adherence of said first and second portions is specified to occur on at least one of said more than two exposures other than said first exposure, to provide reduction of pulling effects otherwise transmitted along said second portion;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

2. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising;

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material; and

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming and adhering said second portion to said first portion upon more than two passes of said beam of said synergistic stimulation, said more than two passes including a first pass, wherein adherence of said first and second portions is specified to occur on at least one of said more than two passes other than said first pass, to provide reduction of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said beam of said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

3. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming and adhering said second portion to said first portion upon a plurality of exposures to the synergistic stimulation, said plurality of exposures including a first exposure, and also including at least one non-uniform exposure, whereupon adherence of said first and second portions is specified to occur on at least one of said plurality of exposures other than said first exposure, to provide reduction of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

4. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming and adhering said second portion to said first portion upon a plurality of passes of said beam of said synergistic stimulation, each pass specified to result in a corresponding exposure of the material to the synergistic stimulation, said plurality of passes including a first pass, and also including at least one pass specified to result in a corresponding non-uniform exposure of said material, whereupon adherence of said first and second portions is specified to occur during at least one of said plurality of passes other than said first pass, to provide reduction of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said beam of said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

5. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming said second portion upon selective exposure of the material to the beam of synergistic stimulation including tracing at least one vector with a plurality of passes of said beam, said plurality of passes including a first pass, and each pass of said plurality specified to result in a corresponding exposure of the material to the synergistic stimulation, wherein adherence of said first and second portions is specified to occur during at least one of said plurality of passes other than said first pass, to provide reduction of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said beam of said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

6. The apparatus of claim 5 wherein said at least one vector has at least a first portion and a second portion, and said at least one computer is programmed to specify tracing said first portion of said at least one vector with said plurality of passes of said beam before any tracing of said second portion of said at least one vector with said beam.

7. The apparatus of claim 5 wherein said at least one vector comprises at least one hatch vector and at least one boundary vector, and said at least one computer is programmed to specify tracing only said at least one hatch vector with said plurality of passes of said beam.

8. The apparatus of claim 5 wherein said at least one computer is programmed to specify tracing said at least one vector with two passes of said beam.

9. The apparatus of claim 7 wherein said at least one computer is programmed to specify tracing said at least one boundary vector with two passes of said beam.

10. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first and second portions spaced from each other, and forming rivets to attach said first and second portions, to reduce pulling effects otherwise transmitted along said first portion;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

11. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first, second, third, and fourth adjacent portions, to obtain tailored object defining data, specifying forming said first, second, third, and fourth portions spaced from each other, forming a first support line connecting said first and second portions, forming a second support line connecting said third and fourth portions, and forming rivets to attach said first and second support lines, to provide for isolation of pulling effects otherwise transmitted along said portions; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

12. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first portion, forming said second portion spaced from said first portion upon selective exposure of the material to the synergistic stimulation including tracing at least one vector with said beam of synergistic stimulation, said tracing specified to result in a corresponding exposure of the material to the beam of synergistic stimulation, and forming at least one rivet along said at least one vector to attach said first and second portions to provide for reduction of pulling effects otherwise transmitted along said portions; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

13. The apparatus of claim 12 wherein said at least one vector has a width, and said at least one computer is programmed to specify forming said at least one rivet with a diameter which is specified to be less than said width of said at least one vector.

14. The apparatus of claim 12 wherein said at least one vector comprises at least one boundary vector and at least one hatch vector, each having a width, wherein said at least one computer is programmed to specify forming said at least one rivet having a diameter which is only specified to be less than said width of said at least one boundary vector.

15. The apparatus of claim 12 wherein said second portion of said desired object has a boundary, and said at least one vector comprises at least one boundary vector specified to be situated along said boundary of said second portion, and said at least one computer is programmed to specify offsetting said at least one rivet from said at least one vector to prevent said at least one rivet from otherwise extending beyond said boundary of said second portion.

24. The apparatus of claim 12 wherein said at least one vector intersects a second vector at an intersection point, and said at least one computer is programmed to specify offsetting said at least one rivet from said intersection point by a predetermined distance.

25. The apparatus of claim 12 wherein said at least one computer is programmed to specify tracing said at least one vector with at least one pass of said beam, and to specify forming said at least one rivet by exposing selected areas along said at least one vector to at least one additional pass of said beam.

16. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions spaced from each other by about 40 to 300 mils, and forming secondary structure to attach said first and second portions, to provide reduction of pulling effects otherwise transmitted along said first portion; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

17. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first and second portions spaced from each other, forming a first support line extending from the first portion, forming a second support line extending from the second portion and overlapping, at least in part, said first support line at an area, and forming at least one rivet at said area to attach said first and second support lines, to provide for reduction of pulling effects otherwise transmitted along said first portion;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

18. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said portion of said data specifying a solid portion of said object, to obtain tailored object defining data, wherein said tailored object defining data specifies inserting of breaks of about 5 to 50 mils in length in said solid portion, and also specifies forming solid sub-portions between said breaks of about 40-300 mils in length, which are isolated from each other by said breaks, to provide isolation of pulling effects otherwise transmitted along said solid portion;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

19. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said portion of said data specifying a solid portion of said object, to obtain tailored object defining data, which specifies inserting bends in said solid portion, resulting in gaps of about 5-50 mils in length, and solid sub-portions of about 40-300 mils in length between the gaps, said gaps and sub-portions being spaced along a straight line through said solid portion, to provide reduction of pulling effects otherwise transmitted along said solid portion;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for receiving said tailored object defining data and for selectively exposing layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

20. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first and second solid adjacent portions, to obtain tailored object defining data specifying forming said first portion, forming said second portion, by selectively exposing said material to a first exposure of said synergistic stimulation with breaks inserted in said portion specified to result in solid sub-portions between the breaks the breaks which are isolated from each other by the breaks, filling said breaks with said material, and exposing said material in said breaks at a lower exposure than said first exposure, to provide isolation of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

21. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first and second solid adjacent portions, to obtain tailored object defining data specifying forming said first and second portions with breaks inserted in said portions, with solid sub-portions specified to be between the breaks and isolated by the breaks, whereupon said breaks in said first portion are specified, at least in part, to be offset from said breaks in said second portion, to provide reduction of pulling effects otherwise transmitted along said first portion; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

22. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first and second adjacent solid portions, to obtain tailored object defining data specifying forming said first portion, and forming said second portion with bends inserted in said second portion to provide reduction of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

23. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying inserting bends in said first and second portions, wherein the bends in said first portion are specified to be offset, at least in part, from the bends in said second portion, to provide for reduction of pulling effects otherwise transmitted along said portions of said object;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for receiving said tailored object defining data and for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

26. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first and second solid adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming said second portion upon selective exposure of the material to the beam of synergistic stimulation including tracing at least one vector with breaks inserted in said at least one vector, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, to provide isolation of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data, and for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

27. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first and second adjacent solid portions, to obtain tailored object defining data specifying forming said first portion, and forming said second portion upon selective exposure of the material to the synergistic stimulation including tracing at least one vector with said beam with bends inserted in said at least one vector, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, to provide reduction of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data, and for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

28. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first and second adjacent solid portions, to obtain tailored object defining data specifying forming said first portion, forming said second portion spaced from said first portion, and forming secondary structure upon selective exposure of the material to the synergistic stimulation including tracing at least one vector with said beam, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, and said secondary structure specified to attach said first and second portions to provide reduction of pulling effects otherwise transmitted along said portions; and

means for receiving said tailored object defining data, and for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

29. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming said second portion upon selective exposure of the material to the synergistic stimulation including tracing at least one vector in a pattern with said beam, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, and said pattern being adapted to provide isolation of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data, and for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

30. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having first and second adjacent solid portions, to obtain tailored object defining data specifying forming said first and second portions spaced from each other, and selectively tracing at least one vector with said beam of said synergistic stimulation, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, and said tracing specified to adhere said first and second portions in a manner adapted to provide reduction of pulling effects otherwise transmitted along said second portion; and

means for receiving said tailored object defining data, and for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

31. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming and adhering said second portion to said first portion upon more than two exposures to the synergistic stimulation, said more than two exposures including a first exposure, whereupon adherence of said first and second portions is specified to occur on at least one of said more than two exposures other than said first exposure, to provide reduction of pulling effects otherwise transmitted along said first portion;

providing a source of said synergistic stimulation;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

32. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of a beam of said synergistic stimulation;

successively forming layers of said material; and

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming and adhering said second portion to said first portion upon more than two passes of said beam of said synergistic stimulation, said more than two passes including a first pass, wherein adherence of said first and second portions is specified to occur on at least one of said more than two passes other than said first pass, to provide reduction of pulling effects otherwise transmitted along said second portion; and

selectively exposing said layers of said material to said beam of said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

33. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of said synergistic stimulation;

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming and adhering said second portion to said first portion upon a plurality of exposures to the synergistic stimulation, said plurality of exposures including a first exposure, and also including at least one non-uniform exposure, whereupon adherence of said first and second portions is specified to occur on at least one of said plurality of exposures other than said first exposure, to provide reduction of pulling effects otherwise transmitted along said first portion; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

34. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of a beam of said synergistic stimulation;

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming and adhering said second portion to said first portion upon a plurality of passes of said beam of said synergistic stimulation, each pass of said plurality of passes specified to result in a corresponding exposure of the material to the synergistic stimulation, and said plurality of passes including a first pass, and also including at least one pass specified to result in a corresponding non-uniform exposure, whereupon adherence of said first and second portions is specified to occur during at least one of said plurality of passes other than said first pass, to provide reduction of pulling effects otherwise transmitted along said second portion; and

selectively exposing said layers of said material to said beam of said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

35. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of a beam of said synergistic stimulation;

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming said second portion upon selective exposure of the material to the beam of synergistic stimulation including tracing at least one vector with a plurality of passes of said beam, each pass of said plurality specified to result in a corresponding exposure of the material to the synergistic stimulation, said plurality including a first pass, wherein adherence of said first and second portions is specified to occur during at least one of said plurality of passes other than said first pass, to provide reduction of pulling effects otherwise transmitted along said first portion; and

selectively exposing said layers of said material to said beam of said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

36. The method of claim 35 wherein said at least one vector has at least a first portion and a second portion, and said modifying step includes the substep of specifying tracing said first portion of said at least one vector with said plurality of passes of said beam before any tracing of said second portion of said at least one vector with said beam.

37. The method of claim 35 wherein said at least one vector comprises at least one hatch vector and at least one boundary vector, and said modifying step includes the substep of specifying tracing only said at least one hatch vector with said plurality of passes of said beam.

38. The method of claim 35 wherein said modifying step includes the substep of specifying tracing said at least one vector with two passes of said beam.

39. The method of claim 37 wherein said modifying step includes the substep of specifying tracing said at least one boundary vector with two passes of said beam.

40. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first and second portions spaced from each other, and forming rivets to attach said first and second portions, to reduce pulling effects otherwise transmitted along said first portion;

providing a source of said synergistic stimulation;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

41. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data descriptive of a desired object, said desired object having first, second, third, and fourth adjacent portions, to obtain tailored object defining data, specifying forming said first, second, third, and fourth portions spaced from each other, forming a first support line connecting said first and second portions, forming a second support line connecting said third and fourth portions, and forming rivets to attach said first and second support lines, to provide for isolation of pulling effects otherwise transmitted along said portions; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

42. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of a beam of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data descriptive of a desired object, said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming said second portion spaced from said first portion upon selective exposure of the material to the synergistic stimulation including tracing at least one vector with said beam of synergistic stimulation, said tracing specified to result in a corresponding exposure of the material to the beam of synergistic stimulation, and forming at least one rivet along said at least one vector to attach said first and second portions to provide for reduction of pulling effects otherwise transmitted along said portions; and

selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

43. The method of claim 42 wherein said at least one vector has a width, and said modifying step includes the substep of specifying forming said at least one rivet with a diameter which is specified to be less than said width of said at least one vector.

44. The method of claim 42 wherein said at least one vector comprises at least one boundary vector and at least one hatch vector, each having a width, wherein said modifying step includes the substep of specifying forming said at least one rivet having a diameter which is only specified to be less than said width of said at least one boundary vector.

45. The method of claim 42 wherein said second portion of said desired object has a boundary, and said at least one vector comprises at least one boundary vector specified to be situated along said boundary of said second portion, and said modifying step includes the substep of specifying offsetting said at least one rivet from said at least one vector to prevent said at least one rivet from otherwise extending beyond said boundary of said second portion.

54. The method of claim 42 wherein said at least one vector intersects a second vector at an intersection point, and said modifying step includes the substep of specifying offsetting said at least one rivet from said intersection point by a predetermined distance.

55. The method of claim 42 wherein said modifying step includes the substeps of specifying tracing said at least one vector to at least one pass of said beam, and specifying forming said at least one rivet by exposing selected areas along said at least one vector to at least one additional pass of said beam.

46. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions spaced from each other by about 40 to 300 mils, and forming secondary structure to attach said first and second portions, to provide reduction of pulling effects otherwise transmitted along said first portion; and

selectively exposing said layers of said material to synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

47. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first and second portions spaced from each other, forming a first support line extending from the first portion, forming a second support line extending from the second portion and overlapping, at least in part, said first support line at an area, and forming at least one rivet at said area to attach said first and second support lines, to provide for reduction of pulling effects otherwise transmitted along said first portion;

providing a source of said synergistic stimulation;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

48. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said portion of said data specifying a solid portion of said object, to obtain tailored object defining data, wherein said tailored object defining data specifies inserting breaks of about 5 to 50 mils in length in said solid portion, and also specifies forming solid sub-portions between said breaks of about 40-300 mils in length, which sub-portions are specified to be isolated from each other by said breaks, to provide isolation of pulling effects otherwise transmitted along said solid portion;

providing a source of said synergistic stimulation;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

49. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said portion of said data specifying a solid portion of said object, to obtain tailored object defining data, which specifies inserting bends in said solid portion, specified to result in forming gaps of about 5-50 mils in length, and forming solid sub-portions of about 40-300 mils in length between the gaps, said gaps and sub-portions specified to be spaced along an approximately straight line through said solid portion, to provide reduction of pulling effects otherwise transmitted along said solid portion;

providing a source of said synergistic stimulation;

successively forming layers of said material; and

selectively exposing layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

50. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data descriptive of a desired object, said desired object having first and second solid adjacent portions, to obtain tailored object defining data specifying forming said first portion, forming said second portion upon a first exposure of said material to said synergistic stimulation with breaks specified to be inserted in said portion resulting in solid sub-portions isolated from each other by the breaks, filling said breaks with said material, and exposing said material in said breaks at a lower exposure than said first exposure, to provide isolation of pulling effects otherwise transmitted along said second portion; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

51. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data descriptive of a desired object, said desired object having first and second solid adjacent portions, to obtain tailored object defining data specifying forming said first and second solid portions with breaks inserted in said portions, and specified to result in solid sub-portions isolated from each other by the breaks, whereupon said breaks in said first portion are specified, at least in part, to be offset from said breaks in said second portion, to provide reduction of pulling effects otherwise transmitted along said first portion; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

52. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of said synergistic stimulation;

means for successively forming layers of said material;

modifying object defining data descriptive of a desired object, said desired object having first and second adjacent solid portions, to obtain a tailored object defining data specifying forming said first portion, and also forming said second portion with bends inserted in said second portion to provide reduction of pulling effects otherwise transmitted along said second portion; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

53. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying inserting bends in said first and second portions, wherein the bends in said first portion are specified to be offset, at least in part, from the bends in said second portion, to provide for reduction of pulling effects otherwise transmitted along said portions of said object;

providing a source of said synergistic stimulation;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

56. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of a beam of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data descriptive of a desired object, said desired object having first and second solid adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming said second portion upon selective exposure of the material to the beam of synergistic stimulation, including tracing at least one vector with breaks inserted in said at least one vector, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, to provide isolation of pulling effects otherwise transmitted along said second portion; and

selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining said to form said three-dimensional object substantially layer-by-layer.

57. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of a beam of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data descriptive of a descried object, said desired object having first and second adjacent solid portions, to obtain a tailored object defining data specifying forming said first portion, and forming said second portion upon selective exposure of the material to the synergistic stimulation including tracing at least one vector with said beam with bends inserted in said at least one vector, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, to provide reduction of pulling effects otherwise transmitted along said second portion; and

selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

58. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of a beam of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data descriptive of a desired object, said desired object having first and second adjacent solid portions, to obtain tailored object defining data specifying forming said first portion, forming said second portion spaced from said first portion, and forming secondary structure upon selective exposure of the material to the synergistic stimulation including tracing at least one vector with said beam, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, and said secondary structure specified to attach said first and second portions to provide reduction of pulling effects otherwise transmitted along said portions; and

selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

59. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of a beam of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data descriptive of a desired object, said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming said second portion upon selective exposure of the material to the synergistic stimulation including tracing at least one vector in a pattern, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, and said pattern being adapted to provide isolation of pulling effects otherwise transmitted along said second portion; and

selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

60. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

providing a source of a beam of said synergistic stimulation;

successively forming layers of said material;

modifying object defining data descriptive of a desired object, said desired object having first and second adjacent solid portions, to obtain tailored object defining data specifying forming said first and second portion spaced from each other, and selectively exposing said material by tracing at least one vector with said beam of said synergistic stimulation, said tracing specified to result in a corresponding exposure of the material to the synergistic stimulation, and said tracing specified to adhere said first and second portions in a manner adapted to provide reduction of pulling effects otherwise transmitted along said second portion; and

selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

61. A method for measuring curl comprising the steps of:

building a plurality of quarter cylinders utilizing a stereolithographic apparatus, each quarter cylinder of said plurality built with a corresponding cure depth;

measuring a curl factor for each of said plurality of quarter cylinders to obtain a plurality of measured quarter cylinders corresponding to each quarter cylinder;

associating said measured curl factors with the cure depths used to build the corresponding quarter cylinder; and

plotting each of said measured curl factors with the cure depth associated with that measured curl factor.

62. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising:

at least one computer programmed to modify at least a portion of object defining data descriptive of a desired object, said desired object having a solid portion, to obtain tailored object defining data, wherein said tailored object defining data specifies insertion of breaks in said solid portion and also specifies solid sub-portions between said breaks which are isolated from each other by the breaks, to provide isolation of pulling effects otherwise transmitted along said solid portion;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

63. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising:

at least one computer programmed to modify at least a portion of object defining data descriptive of a desired object, said desired object having a solid portion, to obtain tailored object defining data, which specifies insertion of bends in said solid portion, to provide reduction of pulling effects otherwise transmitted along said solid portion;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

64. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data descriptive of a desired object, said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions spaced from each other, and also forming secondary structure to attach said first and second portions, to reduce pulling effects otherwise transmitted along at least one of said portions;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

65. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desire object, and said desired object having first and second adjacent portions, to obtain tailored object defining data, specifying forming said first portion, and forming and adhering said second portion to said first portion upon a plurality of exposures of said material to the synergistic stimulation, said plurality including a first exposure, whereupon adherence between said first and second portions is specified to occur on at least one of said plurality of exposures other than said first exposure, to provide reduction of pulling effects otherwise transmitted along at least one of said portions;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

66. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming and adhering said second portion to said first portion upon a plurality of passes of said beam of said synergistic stimulation, each pass of said plurality specified to result in a corresponding exposure of the material to the synergistic stimulation, and said plurality including a first pass, wherein adherence of said first and second portions is specified to occur during at least one of said plurality of passes other than said first pass, to provide reduction of pulling effects otherwise transmitted along at least one of said portions; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

67. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, to obtain tailored object defining data specifying forming at least a portion of said object having a structure adapted to provide for reduction of pulling effects otherwise transmitted along said portion of said object;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

68. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions, and adhering said second portion to said first portion in a manner adapted to provide for reduction of pulling effects otherwise transmitted along at least one of said portions;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

69. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising:

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, said desired object having a solid portion, to obtain tailored object defining data specifying forming said portion with breaks inserted in said portion upon a first exposure of said material to said synergistic stimulation, said data also specifying forming solid sub-portions between said breaks and isolated from each other by said breaks, with material in said breaks, and exposing said material in said breaks at a lower exposure than said first exposure, to provide reduction of pulling effects otherwise transmitted along said portion; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

70. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising:

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having a solid portion, to obtain tailored object defining data, which specifies forming said solid portion with bends inserted in said solid portion upon a first exposure of said material to said synergistic stimulation, with material in said bends, and exposing said material in said bends at a lower exposure than said first exposure, to provide reduction of pulling effects otherwise transmitted along said portion;

a container of said material;

a source of said synergistic stimulation;

means for successively forming layers of said material; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

71. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify object defining data descriptive of a desired object, to obtain tailored object defining data specifying forming at least a portion of said object upon selective exposure of the material to the beam of synergistic stimulation including selectively tracing at least one line with said beam with breaks inserted in said at least one line, said selective tracing specified to result in a corresponding exposure of said material to said beam of synergistic stimulation, to provide isolation of pulling effects otherwise transmitted along said portion; and

means for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

72. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, to obtain tailored object defining data specifying forming at least a portion of said object upon selective exposure of the material to the beam of synergistic stimulation including selectively tracing at least one line with said beam with bends inserted in said at least one line, said selective tracing specified to result in a corresponding exposure of said material to said beam of synergistic stimulation, to provide reduction of pulling effects otherwise transmitted along said portion; and

means for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

73. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions spaced from each other upon selective exposure of the material to the beam of synergistic stimulation, including selectively tracing at least first and second lines with said beam of said synergistic stimulation, said selective tracing specified to result in corresponding first and second lines of transformed material in said first and second portions, respectively, said data also specifying forming secondary structure to attach said first and second portions along said first and second lines, to provide reduction of pulling effects otherwise transmitted along at least one of said portions; and

means for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

74. A stereolithographic apparatus for forming a three-dimensional object substantially layer by layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising;

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming and adhering said second portion to said first portion upon selective exposure of the material to the beam of synergistic stimulation including tracing at least one line with a plurality of passes of said beam, each pass of said plurality specified to result in a corresponding exposure of the material to the beam of synergistic stimulation, and said plurality including a first pass, wherein adherence of said first and second portions is specified to occur during at least one of said plurality of passes other than said first pass, to provide reduction of pulling effects otherwise transmitted along at least one of said portions; and

means for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

75. A stereolithographic apparatus for forming a three-dimensional object substantially layer by layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, to obtain tailored object defining data specifying forming at least a portion of said object upon selective exposure of the material to the beam of the synergistic stimulation including selectively tracing at least one line with the beam of said synergistic stimulation in a pattern, said selective tracing specified to result in a corresponding exposure of the material to the beam of synergistic stimulation, and said pattern being adapted to provide reduction of pulling effects otherwise transmitted along said portion; and

means for selectively exposing said layers of said material to said synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

76. A stereolithographic apparatus for forming a three-dimensional object substantially layer by layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation comprising:

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions, upon selective exposure of the material to the beam of synergistic stimulation including tracing at least first and second lines with a beam of said synergistic stimulation, said tracing specified to result in corresponding lines of transformed material in said first and second portions, respectively, said data also specifying adhering said first and second portions along said first and second lines in a manner adapted to provide reduction of pulling effects otherwise transmitted along at least one of said portions; and

means for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

77. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising:

a container of said material;

a source of a beam o said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having a solid portion, to obtain tailored object defining data specifying forming said portion upon a first exposure of the material to the beam of synergistic stimulation including selectively tracing at least one line with said beam with breaks inserted in said at least one line, said selective tracing specified to result in a corresponding exposure of the material to the beam of synergistic stimulation and specified to form solid sub-portions of said object isolated from each other by breaks, with material in said breaks, and exposing said material in said breaks at a lower exposure than said first exposure, to provide reduction of pulling effects otherwise transmitted along said portion; and

means for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

78. A stereolithographic apparatus for forming a three-dimensional object substantially layer-by-layer out of a material capable of physical transformation upon selective exposure to synergistic stimulation comprising;

a container of said material;

a source of a beam of said synergistic stimulation;

means for successively forming layers of said material;

at least one computer programmed to modify at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having a solid portion, to obtain tailored object defining data specifying forming said portion upon a first exposure of said material to said beam of synergistic stimulation including tracing at least one line with bends inserted in said at least one line with said beam of said synergistic stimulation, said tracing specified to result in a corresponding exposure of said material to said beam of synergistic stimulation to provide a corresponding at least one line of said object with bends inserted, with material in said bends, and exposing said material in said bends to said beam of synergistic stimulation at a lower exposure than said first exposure, to provide reduction of pulling effects otherwise transmitted along said portion; and

means for selectively exposing said layers of said material to said beam of synergistic stimulation from said source in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

79. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said object having a solid portion, to obtain tailored object defining data specifying forming said portion with breaks inserted in said portion, and also specifying forming solid sub-portions of said object between said breaks specified to be isolated from each other by said breaks, to provide isolation of pulling effects otherwise transmitted along said solid portion;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

80. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having a solid portion, to obtain tailored object defining data specifying forming said portion with bends inserted in said portion to provide reduction of pulling effects otherwise transmitted along said portion;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

81. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a described object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions, and also forming secondary structure to attach said first portion to said second portion, to provide reduction of pulling effects otherwise transmitted along at least one of said portions;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

82. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a described object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming and adhering said second portion to said first portion upon a plurality of exposures of the material to the synergistic stimulation, said plurality including a first exposure, whereupon adherence of said first and second portions is specified to occur during at least one of said plurality of exposures other than said first exposure, to provide reduction of pulling effects otherwise transmitted along at least one of said portions;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

83. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming and adhering said second portion to said first portion upon a plurality of passes of a beam of said synergistic stimulation, each of said passes of said plurality specified to result in a corresponding exposure of the material to the synergistic stimulation, and said plurality of passes including a first pass, wherein adherence of said first and second portions is specified to occur during at least one of said plurality of passes other than said first pass, to provide reduction of pulling effects otherwise transmitted along at least one of said portions; and

selectively exposing said layers of said material to said beam of said synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

84. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, to obtain tailored object defining data specifying forming at least a portion of said object with a structure adapted to provide isolation of pulling effects otherwise transmitted along said portion of said object;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

85. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions, and adhering said first portion to said second portion in a manner adapted to provide reduction of pulling effects otherwise transmitted along at least one of said portions of said object;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

86. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having solid portion, to provide tailored object defining data specifying forming said portion with breaks inserted in said portion upon a first exposure of the material to the synergistic stimulation, said data further specifying forming solid sub-portions of the object between the breaks which are specified to be isolated by said breaks, with material in said breaks, and exposing said material in said breaks at a lower exposure than said first exposure to provide reduction of pulling effects otherwise transmitted along said portion; and

selectively exposing said layers of said material to said synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

87. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having a solid portion, to obtain tailored object defining data specifying forming said portion with bends inserted in said portion upon a first exposure to said synergistic stimulation, with material in said bends, and exposing said material in said bends to said synergistic stimulation at a lower exposure than said first exposure, to provide reduction of pulling effects otherwise transmitted along said portion;

successively forming layers of said material; and

selectively exposing said layers of said material to said synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

88. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material; and

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having a solid portion, to obtain tailored object defining data specifying forming said portion of said object upon selective exposure of the material to a beam of the synergistic stimulation including tracing at least one line with the beam of said synergistic stimulation with breaks inserted in said at least one line, said tracing specified to result in a corresponding exposure of the material to the beam of synergistic stimulation, and specified to form solid sub-portions of the object between and isolated from each other by breaks, to provide isolation of pulling effects otherwise transmitted along said portion; and

selectively exposing said layers of said material to said beam of synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

89. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material; and

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having a solid portion, to obtain tailored object defining data specifying forming said portion upon selective exposure of the material to a beam of the synergistic stimulation including tracing at least one line with bends inserted in said at least one line, said tracing specified to result in a corresponding exposure of the material to the beam of synergistic stimulation, to provide reduction of pulling effects otherwise transmitted along said portion; and

selectively exposing said layers of said material to said beam of synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

90. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions spaced from each other upon selective exposure of the material to a beam of the synergistic stimulation including tracing at least first and second lines with the beam of said synergistic stimulation, said tracing specified to result in corresponding first and second lines of transformed material in said first and second portions, respectively, said data also specifying forming secondary structure to attach said first and second portions along said first and second lines, to provide reduction of pulling effects otherwise transmitted along at least one of said portions; and

selectively exposing said layers of said material to said beam of synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

91. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first portion, and forming and adhering said second portion to said first portion upon selective exposure of the material to a beam of the synergistic stimulation including tracing at least one line with a plurality of passes of the beam of said synergistic stimulation, each pass of said plurality specified to result in a corresponding exposure of the material to the beam of synergistic stimulation, and said plurality including a first pass, whereupon adherence of said first and second portions is specified to occur during at least one of said passes other than said first pass to provide reduction of pulling effects otherwise transmitted along at least one of said portions; and

selectively exposing said layers of said material to said beam of synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

92. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, to obtain tailored object defining data specifying forming at least a portion of said object upon selective exposure of the material to a beam of the synergistic stimulation including selectively tracing at least one line with the beam of said synergistic stimulation in a pattern, said tracing specified to result in a corresponding exposure of the material to the beam of synergistic stimulation, and said pattern being adapted to provide reduction of pulling effects otherwise transmitted along said portion; and

selectively exposing said layers of said material to said beam of synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

93. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having first and second adjacent portions, to obtain tailored object defining data specifying forming said first and second portions upon selective exposure of the material to a beam of the synergistic stimulation including tracing at least first and second lines with the beam of said synergistic stimulation, said trading specified to result in corresponding first and second lines of transformed material in said first and second portions, respectively, said data also specifying adhering said first and second portions along said first and second lines in a manner adapted to provide reduction of pulling effects otherwise transmitted along at least one of said portions; and

selectively exposing said layers of said material to said beam of synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

94. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer out of a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having a solid portion, to obtain tailored object defining data specifying forming said solid portion upon a first exposure of the material to a beam of the synergistic stimulation including selectively tracing at least one line with the beam of said synergistic stimulation with breaks inserted in said at least one line, said selective tracing specified to result in a corresponding exposure of the material to the beam of synergistic stimulation to provide solid sub-portions of the object between and isolated from each other by breaks, with material in said breaks, and exposing said material in said breaks to said beam of synergistic stimulation at a lower exposure than said first exposure, to provide isolation of pulling effects otherwise transmitted along said portion; and

selectively exposing said layers of said material to said beam of synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.

95. A stereolithographic method for forming a three-dimensional object substantially layer-by-layer from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:

successively forming layers of said material;

modifying at least a portion of object defining data, said data being descriptive of a desired object, and said desired object having a solid portion, to obtain tailored object defining data specifying forming said portion upon a first exposure of the material to a beam of the synergistic stimulation including tracing at least one line with bends inserted in said line with said beam of said synergistic stimulation, said tracing specified to result in a corresponding exposure of the material to the beam of synergistic stimulation to provide a corresponding line of said object with bends inserted, with material in said bends, and exposing said material in said bends to said beam of synergistic stimulation at a lower exposure than said first exposure, to provide reduction of pulling effects otherwise transmitted along said portion; and

selectively exposing said layers of said material to said beam of synergistic stimulation in accordance with said tailored object defining data to form said three-dimensional object substantially layer-by-layer.