Scan Tools > Surface and Curve Manipulation > Modifying Surfaces > To Set Boundary Constraints for Surface Modification
  
To Set Boundary Constraints for Surface Modification
You can define constraints for each surface boundary.
1. Click Edit > Modify in Scan Tools.
2. Select a spline surface. The Modify Surface dialog box opens.
3. Click Boundaries Constraints on the Modify Surface dialog box.
4. Under Constraints, select a boundary from the list. The selected boundary is highlighted in red.
5. From the list, select a constraint that you want to assign to the selected boundary. Select from the following:
Free—No conditions are specified.
Position—The boundary is fixed in its current position.
Tangent—Sets tangency between the boundary and the reference surface. You can select only a one-sided edge as a reference boundary.
Curvature—Sets G2 continuity and tangency between the boundary and the reference surface. You can select only a one-sided edge as a reference boundary.
Normal—Scan Tools aligns the boundary to the selected plane so that normals along that boundary are parallel to the plane.
6. To set the conditions, click the selection arrow.
7. Select a condition from the CONDITIONS menu and click Done:
KeepGrid—Aligns the surface along the existing gridlines without adding new gridlines.
WithinTol—Aligns the surface to the reference boundary so that the deviation is within the part accuracy. When aligning the surface, Scan Tools keeps adding gridlines until the alignment and tangency are within the tolerance.
8. Click .