Representation and discovery of geometric relationships in a three dimensional model

1. A method for maintaining equivalence relations, comprising:

receiving, in a product data management (PDM) system, a 3D model including a plurality of components;

receiving, by the PDM system, a selection of one of the plurality of components of the model;

receiving, by the PDM system, a selection of at least one equivalence relation, from a set of equivalence relations having a defined strength hierarchy, to be discovered in the 3D model;

identifying, by the PDM system, at least one target component of the plurality of components of the model;

completing the selected component with respect to each target component, by the PDM system, according to each selected equivalence relation to automatically identify equivalence relationships between the selected component and each target component, wherein the automatic identification of equivalence relationships includes performing a geometric test associated with a strongest selected equivalence relationship in the defined strength hierarchy, and in response to determining the selected component and a target component do not share the strongest selected equivalence relationship, performing a second geometric test on the selected component and the target component, the second geometric test being associated with a next-strongest selected equivalence relationship; and

building and storing an equivalence relationship graph, by the PDM system, according to the completed selected component, including the identified equivalence relationships.

2. The method of claim 1 , wherein the PDM system edits the model while maintaining the selected equivalence relations.

3. The method of claim 1 , wherein completing the selected component includes comparing the selected component to each target component with respect to each selected equivalence relation.

4. The method of claim 1 , wherein the at least one equivalence relation is one or more of Identical (I), Same Center (SC), Same Axis (SA), Same Plane (SP), and Same Direction (SD).

5. The method of claim 1 , wherein the PDM system completes each of the target components according to each selected equivalence relation.

6. The method of claim 1 , wherein the at least one equivalence relation is selected from the set of equivalence relations including Identical (I), Same Center (SC), Same Axis (SA), Same Plane (SP), and Same Direction (SD), and the defined strength hierarchy of the equivalence relations is, from strongest to weakest, I, SC, SA, SP, and SD.

7. The method of claim 6 , wherein when one equivalence relation is met between any two components of the model, then all weaker equivalence relations are met between those two components.

8. A product data management (PDM) system comprising:

at least one processor; and

an accessible memory, the PDM system configured to:

receive a 3D model including a plurality of components;

receive a selection of one of the plurality of components of the model;

receive a selection of at least one equivalence relation, from a set of equivalence relations having a defined strength hierarchy, to be discovered in the 3D model;

identify at least one target component of the plurality of components of the model;

complete the selected component with respect to each target component according to each selected equivalence relation to automatically identify equivalence relationships between the selected component and each target component, wherein the automatic identification of equivalence relationships includes performing a geometric test associated with a strongest selected equivalence relationship in the defined strength hierarchy, and in response to determining the selected component and a target component do not share the strongest selected equivalence relationship, performing a second geometric test on the selected component and the target component, the second geometric test being associated with a next-strongest selected equivalence relationship; and

build and store an equivalence relationship graph according to the completed selected component, including the identified equivalence relationships.

9. The PDM system of claim 8 , wherein the system edits the model while maintaining the selected equivalence relations.

10. The PDM system of claim 8 , wherein completing the selected component includes comparing the selected component to each target component with respect to each selected equivalence relation.

11. The PDM system of claim 8 , wherein the at least one equivalence relation is one or more of Identical (I), Same Center (SC), Same Axis (SA), Same Plane (SP), and Same Direction (SD).

12. The PDM system of claim 8 , wherein the PDM system completes each of the target components according to each selected equivalence relation.

13. The PDM system of claim 8 , wherein the at least one equivalence relation is selected from the set of equivalence relations including Identical (I), Same Center (SC), Same Axis (SA), Same Plane (SP), and Same Direction (SD), and the defined strength hierarchy of the equivalence relations is, from strongest to weakest, I, SC, SA, SP, and SD.

14. The PDM system of claim 13 , wherein when one equivalence relation is met between any two components of the model, then all weaker equivalence relations are met between those two components.

15. A non-transitory computer-readable medium encoded with computer-executable instructions that, when executed, cause a product data management (PDM) system to:

receive a 3D model including a plurality of components;

receive a selection of one of the plurality of components of the model;

receive a selection of at least one equivalence relation, from a set of equivalence relations having a defined strength hierarchy, to be discovered in the 3D model;

identify at least one target component of the plurality of components of the model;

complete the selected component with respect to each target component according to each selected equivalence relation to automatically identify equivalence relationships between the selected component and each target component, wherein the automatic identification of equivalence relationships includes performing a geometric test associated with a strongest selected equivalence relationship in the defined strength hierarchy, and in response to determining the selected component and a target component do not share the strongest selected equivalence relationship, performing a second geometric test on the selected component and the target component, the second geometric test being associated with a next-strongest selected equivalence relationship; and

build and store an equivalence relationship graph according to the completed selected component, including the identified equivalence relationships.

16. The computer-readable medium of claim 15 , wherein the PDM system edits the model while maintaining the selected equivalence relations.

17. The computer-readable medium of claim 15 , wherein completing the selected component includes comparing the selected component to each target component with respect to each selected equivalence relation.

18. The computer-readable medium of claim 15 , wherein the at least one equivalence relation is one or more of Identical (I), Same Center (SC), Same Axis (SA), Same Plane (SP), and Same Direction (SD).

19. The computer-readable medium of claim 15 , wherein the PDM system completes each of the target components according to each selected equivalence relation.

20. The computer-readable medium of claim 15 , wherein the at least one equivalence relation is selected from the set of equivalence relations including Identical (I), Same Center (SC), Same Axis (SA), Same Plane (SP), and Same Direction (SD), and the defined strength hierarchy of the equivalence relations is, from strongest to weakest, I, SC, SA, SP, and SD, and wherein when one equivalence relation is met between any two components of the model, then all weaker equivalence relations are met between those two components.