Sketched overdrawn lines for editing spline-based three-dimensional curves

1. A computer program product stored in a non-transitory memory embodying instructions executable by a processor to perform an overdraw method for editing a three-dimensional geometry, the method steps comprising:

receiving a three-dimensional geometry comprising a plurality of individual curves whose positions are defined by a plurality of control points;

receiving a polyline overdrawn on the three-dimensional geometry, the polyline drawing representing edits to the three-dimensional drawing;

analyzing a shape of the received polyline drawing to determine a level of complexity of the shape of the edits to the three-dimensional drawing;

determining whether the complexity of the shape of the edits to the three-dimensional drawing exceeds a predetermined threshold;

rejecting the edits to the three-dimensional drawing when it is determined that the complexity of the shape of the edits exceeds the predetermined threshold; and

when it is determined that the complexity of the shape of the edits does not exceed the predetermined threshold, the three-dimensional geometry is modified according to the edits, the modifying including:

matching the polyline to the three-dimensional geometry to determine a portion of the three-dimensional geometry being modified;

recognizing a shape feature of the polyline to determine a shape modification to apply to the three-dimensional geometry;

shifting the three-dimensional geometry to determine a modified geometry by automatically changing a position of at least one of the control points towards the polyline; and

matching the modified geometry with at least one symmetry operator to determine whether the changed position satisfies a constraint and applying the constraint to the modified geometry to further modify the modified geometry.

2. The computer program product of claim 1 , wherein the polyline has a position placed with respect to a transformed view of the three-dimensional geometry.

3. The computer program product of claim 2 , wherein the transformed view is a two-dimensional view.

4. The computer program product of claim 2 , wherein each of the plurality of individual curves of the transformed view of the three-dimensional geometry is disposed in a corresponding orientation plane, and further wherein the shifting of the three-dimensional geometry is in the orientation plane or perpendicular to the orientation plane of one of the plurality of individual curves nearest the polyline.

5. The computer program product of claim 4 , further comprising selecting between shifting the three-dimensional geometry in the orientation plane or perpendicular to the orientation plane according to an angle formed between the orientation plane and a viewing plane of the transformed view of the three-dimensional geometry.

6. The computer program product of claim 1 , further comprising: determining a distance between the three-dimensional geometry and the polyline at each of a sampling of points along the polyline; and summing the distances to determine a distance metric.

7. The computer program product of claim 6 , further comprising controlling an iteration of the shifting of the three-dimensional geometry according to a change in the distance metric.

8. The computer program product of claim 1 , wherein matching the modified geometry with at least one symmetry operator further comprises:

determining at least one curve of the modified geometry; and

matching the curve of the modified geometry to the constraint, wherein the application of the constraint modifies the curve of the modified geometry to match the constraint.

9. The computer program product of claim 8 , further comprising adding the constraint to a list associated with the three-dimensional geometry.

10. The computer program product of claim 9 , wherein subsequent changes in the position of the three-dimensional geometry are controlled by the list.

11. A computer program embodying instructions executable by a processor to perform an overdraw method for editing a three-dimensional geometry, the method steps comprising:

receiving a three-dimensional geometry comprising a plurality of individual curves whose positions are defined by a plurality of control points;

receiving a polyline overdrawn on the three-dimensional geometry, the polyline drawing representing edits to the three-dimensional drawing;

analyzing a shape of the received polyline drawing to determine a level of complexity of the shape of the edits to the three-dimensional drawing;

determining whether the complexity of the shape of the edits to the three-dimensional drawing exceeds a predetermined threshold;

rejecting the edits to the three-dimensional drawing when it is determined that the complexity of the shape of the edits exceeds the predetermined threshold; and

when it is determined that the complexity of the shape of the edits does not exceed the predetermined threshold, the three-dimensional geometry is modified according to the edits, the modifying including:

modifying, iteratively, the three-dimensional geometry by shifting the three-dimensional geometry to determine a modified geometry approaching a shape feature of the polyline;

matching the modified geometry to a constraint; and

applying the constraint to the modified geometry.

12. The computer program product of claim 11 , further comprising:

determining a distance between the three-dimensional geometry and the polyline at each of a sampling of points along the polyline; and

summing the distances to determine a distance metric.

13. The computer program product of claim 11 , wherein the polyline has a position placed with respect to a transformed view of the three-dimensional geometry.

14. The computer program product of claim 13 , wherein the transformed view is a two-dimensional view.

15. The computer program product of claim 13 , wherein each of the plurality of individual curves of the transformed view of the three-dimensional geometry is disposed in a corresponding orientation plane, and further wherein the shifting of the three-dimensional geometry is in the orientation plane or perpendicular to the orientation plane of one of the plurality of individual curves nearest the polyline.

16. The computer program product of claim 15 , further comprising selecting between shifting the three-dimensional geometry in the orientation plane or perpendicular to the orientation plane according to an angle formed between the orientation plane and a viewing plane of the transformed view of the three-dimensional geometry.