Close error: When distance from the starting point to ending point less than close
tolerance, automatic closing of the curve.
Force to close: Mandatory closure of all selected curves.
2.13.6 Remove The Overlap
Click menu【Handle】->【Delete overlap】,or click ，the dialog box appear.
Under normal circumstances do not select the “Enable Overlap error”. Removing the
overlapping lines when two lines are compared to a good degree of coincidence. If you
need to delete overlapping lines, you should select “Enable Overlap error”, and set
overlap error. Generally do not overlap error set too large, so as to avoid accidental
deletion.
2.13.7 Combine Curve
Click menu【Handle】 /【Combine Curve】，or click
appears.
,the following dialog box
