System and method for analyzing modeling accuracy while performing reverse engineering with 3D scan data

Abstract

An automated mechanism for measuring the amount of accuracy loss attributable to reverse engineering processes that use 3D scan data is discussed. The embodiments provide a mechanism that displays to a user the effect scan data editing and CAD remodeling operations have on scan data accuracy. Additionally, the user can choose the way the graphical display illustrates the error distribution on the model such as by color mapping and whisker mapping. The accuracy loss may be displayed to the user after finishing an editing/modeling command or during the previewing of the command thereby allowing a user to take appropriate action. Parameters may also be adjusted programmatically based on the amount of accuracy loss determined to be attributable to scan data editing or CAD remodeling operations.

We claim: 
     
       1. A computer-readable non-transitory storage medium holding computer-executable instructions for analyzing 3D modeling accuracy when processing 3D scan data, the instructions when executed causing at least one computing device to:
 provide a collection of 3D scan data forming a model representing the shape of a three dimensional object; 
 provide a CAD system being used to remodel at least one CAD part body formed from the 3D scan data; 
 receive a selection of an operation designed to manipulate one of at least a portion of the 3D scan data or at least a portion of the at least one CAD part body, the operation being other than to form the at least one CAD part body from the 3D scan data; 
 determine a measure of loss of accuracy attributable to the selected operation; and 
 present the measure of the loss of accuracy to a user. 
 
     
     
       2. The medium of  claim 1  wherein the model is a mesh model. 
     
     
       3. The medium of  claim 1  wherein the model is a point cloud model. 
     
     
       4. The medium of  claim 1  wherein the instructions when executed further cause the at least one computing device to:
 present the measure of the loss of accuracy as a preview to a user prior to beginning the operation. 
 
     
     
       5. The medium of  claim 1 , wherein the instructions when executed further cause the at least one computing device to:
 execute the selected operation; and  
 present the measure of the loss of accuracy to a user after the completion of the operation. 
 
     
     
       6. The medium of  claim 1  wherein the measure of the loss of accuracy is presented to the user graphically. 
     
     
       7. The medium of  claim 6  wherein the measure of the loss of accuracy is presented to the user via an error map. 
     
     
       8. The medium of  claim 7  wherein the error map is a heat map. 
     
     
       9. The medium of  claim 1  wherein the determining of the loss of accuracy includes comparing an effect of the selected operation against a user-selected tolerance. 
     
     
       10. The medium of  claim 9  wherein the user-selected tolerance is expressed as a range. 
     
     
       11. The medium of  claim 1  wherein the operation is a scan data editing operation. 
     
     
       12. The medium of  claim 11  wherein the operation is a meshing operation. 
     
     
       13. The medium of  claim 12  wherein the meshing operation is one of smoothing, decimation, subdividing, cleaning, re-meshing, de-featuring, filling holes and the smoothing of a boundary. 
     
     
       14. The medium of  claim 11  wherein the measure of the loss of accuracy measures the loss of accuracy of at least one of curvature, deviation and vertex balance occurring in the scan data as result of the performance of the selected operation. 
     
     
       15. The medium of  claim 11  wherein the instructions when executed further cause the at least one computing device to:
 adjust at least one parameter of the selected operation as a result of the determining of the measure of loss of accuracy. 
 
     
     
       16. The medium of  claim 15  wherein the adjusting occurs programmatically without user involvement. 
     
     
       17. The medium of  claim 1  wherein the operation is a CAD remodeling operation. 
     
     
       18. The medium of  claim 17  wherein the CAD remodeling operation is one of fitting a surface to the scan data, placing or drawing curves on the scan data, creating a solid body using the scan data, measuring curvature, measuring deviation, measuring continuity and environment mapping. 
     
     
       19. The medium of  claim 17 , wherein the instructions when executed further cause the at least one computing device to:
 perform an optimization routine so as to adjust at least one parameter of a CAD part body as a result of the determining of the measure of loss of accuracy. 
 
     
     
       20. The medium of  claim 19  wherein the optimization routine is an error minimization routine. 
     
     
       21. The medium of  claim 20 , wherein the instructions when executed further cause the at least one computing device to:
 adjust a CAD part body parameter so as to minimize an amount of error over at least one chosen region. 
 
     
     
       22. The medium of  claim 21  wherein the adjusting occurs programmatically without user involvement. 
     
     
       23. The medium of  claim 1 , wherein the instructions when executed further cause the at least one computing device to:
 update programmatically a measure of the loss of accuracy, the updating occurring when a change in one of the 3D scan data and the at least one CAD part body is attributable to the user selection of the operation. 
 
     
     
       24. A method for analyzing 3D modeling accuracy when processing 3D scan data, comprising:
 providing a collection of 3D scan data forming a model representing the shape of a three dimensional object; 
 providing a CAD system being used to remodel at least one CAD part body formed from the 3D scan data; 
 receiving a selection of an operation designed to manipulate one of at least a portion of the 3D scan data or at least a portion of the at least one CAD part body, the operation being other than to form the at least one CAD part body from the 3D scan data; 
 determining a measure of loss of accuracy attributable to the selected operation; and 
 presenting the measure of the loss of accuracy to a user. 
 
     
     
       25. The method of  claim 24 , further comprising:
 presenting the measure of the loss of accuracy as a preview to a user prior to beginning the operation. 
 
     
     
       26. The method of  claim 24 , further comprising:
 executing the selected operation; and  
 presenting the measure of the loss of accuracy to a user after the completion of the operation. 
 
     
     
       27. The method of  claim 24  wherein the operation is a scan data editing operation. 
     
     
       28. The method of  claim 27  wherein the operation is one of smoothing, decimation, subdividing, cleaning, re-meshing, de-featuring, filling holes and the smoothing of a boundary. 
     
     
       29. The method of  claim 24  wherein the measure of the loss of accuracy is presented to the user graphically. 
     
     
       30. The method of  claim 29  wherein the measure of the loss of accuracy is presented to the user via an error map. 
     
     
       31. The method of  claim 24  wherein the determining of the loss of accuracy includes comparing an effect of the selected operation against a user-selected tolerance value. 
     
     
       32. The method of  claim 24  wherein the measure of the loss of accuracy measures the loss of accuracy of at least one of curvature, deviation and vertex balance occurring in the scan data as result of the performance of the selected operation. 
     
     
       33. The method of  claim 24 , further comprising:
 adjusting at least one parameter of the selected operation as a result of the determining of the measure of loss of accuracy. 
 
     
     
       34. The method of  claim 24  wherein the operation is a CAD remodeling operation. 
     
     
       35. The method of  claim 34  wherein the CAD remodeling operation is one of fitting a surface to the scan data, placing or drawing curves on the scan dataand creating a solid using the scan data, measuring curvature, measuring deviation, measuring continuity and environment mapping. 
     
     
       36. The method of  claim 35 , further comprising:
 performing an optimization routine so as to adjust at least one parameter of a CAD part body as a result of the determining of the measure of loss of accuracy. 
 
     
     
       37. The method of  claim 36  wherein the optimization routine is an error minimization routine. 
     
     
       38. The method of  claim 37 , further comprising:
 adjusting the parameters of the error minimization routine so as to minimize an amount of error over at least one chosen region. 
 
     
     
       39. The method of  claim 24 , further comprising:
 updating programmatically a measure of the loss of accuracy, the updating occurring when a change in one of the 3D scan data and the at least one CAD part body is attributable to the user selection of the operation. 
 
     
     
       40. A system for analyzing 3D modeling accuracy when processing 3D scan data, comprising:
 a computer memory configured to store a collection of 3D scan data forming a model representing the shape of a three dimensional object; and 
 a computing device configured to at least: 
 execute a CAD application being used to remodel at least one CAD part body formed from the 3D scan data; 
 generate a graphical user interface enabling theto enable selection of an operation, the operation being one of a scan data editing operation and CAD remodeling operation, the operation being other than to form the at least one CAD part body from the 3D scan data; and 
 execute an accuracy analysis facility, the accuracy analysis facility measuring to measure a loss of accuracy attributable to the selected operation, the measured loss of accuracy presented to a user. 
 
     
     
       41. The system of  claim 40  wherein the graphical user interface presents is configured to present a measure of the loss of accuracy to a user via a generated error map. 
     
     
       42. The system of claim  40  41 wherein the measure of accuracy displayed presented to the user via the generated error map is programmatically updated when the user selection of an operation results in a change to the 3D scan data or the at least one CAD part body. 
     
     
       43. The system of  claim 40  wherein the graphical user interface presents is configured to present an indication of a measure of the loss of accuracy to a user and the indication of a measure of the loss of accuracy is programmatically updated when the user selection of an operation results in a change to the 3D scan data or the at least one CAD part body.