To Modify a Surface Using Fit
1. Click
Edit >
Modify in Scan Tools.
2. Select a spline surface to modify. The Modify Surface dialog box opens.
3. Click
.
4. Define the movement plane from the Move list. Select from Dynamic Plane, Defined Plane, or Original Plane.
5. In each direction, you can specify the gridlines that Scan Tool uses for fitting the surface.
6. To select gridlines in the first direction, click the 1st Direction Subset Grid check box, select red gridlines, and middle-click.
7. To select gridlines in the second direction, click 2nd Direction Subset Grid, select blue gridlines, and middle-click.
8. To use Fit with the default setting, click Fit. Scan Tools tries to fit the surface.
Optionally, you can define conditions for the fit operation by specifying the Options and Reference Points Setup settings in the Modify Surface dialog box.
9. To set accuracy, type the accuracy value in the Accuracy box.
10. To set the offset, type the offset value in the Offset box.
11. To add reference points, click Add Ref Points under Reference Points Setup.
12. To specify reference points, select one of the following from the list:
◦ Raw Data Set—Selects points from a raw data set.
◦ Raw Data Points—Selects individual points from a raw data set.
◦ Single Point—Selects datum points.
◦ Datum Points Array—Selects an entire datum point array.
◦ Facet Vertices—Selects vertices of a faceted model.
|  Click Diagnostics and turn on the Reference Points display to show reference points on the model. |
13. Click the selection arrow, select reference points to add, and middle-click.
14. If you selected Raw Data Set, the SCAN FILTER menu appears. Select one of the following:
◦ CrvChainFltr—Uses only those scan points that are enclosed within the region bounded by an open or closed chain of curves. Use the CHAIN menu to select curves separating scan points and then select a scan set.
◦ SrfProjFltr—Uses only those scan points that project within the boundaries of the surface. Select a scan set to project onto the surface.
◦ No Fltr—Selects an entire scan set.
15. To remove reference points, click Rmv Ref Points and select one of All, Scan Curve Set, Scan Curve Points, Single Point, Datum Point Array, or By Deviation Range.
16. Click the selection arrow, select reference points to remove, and middle-click.
17. Optionally, click Diagnostics to enable the dynamic display of the selected analyses.
18. Optionally, click Boundaries Constraints to set boundaries constraints.
19. Click OK to finish the operation.