Menu | Edit > Lines > Simplify/Smooth |
Simplify and/or smooth lines with tightly curved or angular line segments.
Lines are simplified by filtering the vertices in the line based on a selected algorithm. When using this option, vertices are removed from the lines if they are not necessary. A number of filtering algorithms are available. For information on each of the algorithms, see Filter Methods.
Smoothing is performed using the bSpline algorithm. When using this option, the distance between vertices is shortened by adding additional vertices. By having shorter edges, smoother curves are achieved.
If using both options, the lines are first filtered and the resulting features are then smoothed.
Changes are only applied to selected features. If those features share geometry with other features, making this change could adversely affect the topology of your data because the changes will not be applied to the other features sharing the geometry. |
Interface
The Simplify/Smooth command uses the following dialog box.
Option | Description |
|---|---|
Filter | This option is used to apply filtering to the vertices in the selected contours. You can choose the algorithm by which to apply filtering, and whether to filter by metres on the ground or by millimetres (mm) at map scale, which requires you to enter a scale. |
Method | The filtering algorithm to be applied. The algorithms available are: • Douglas-Peucker • Reumann-Witkam • Lang • Radius • Opheim |
Tolerance | The number of units by which to perform filtering. Enter a value in the field. |
Edge length | The maximum edge length when filtering using the Opheim method. This field is only enabled when the Opheim filter method is selected. |
Distances are | The distance type to use for filtering. 1. Select either metres on the ground or mm at map scale. If you choose mm at map scale, a value must be entered in the map scale field. |
Look ahead | The number of vertices to be considered when filtering using the Lang method. |
Smooth | This option is used to apply smoothing to the selected contours. A bSpline Order value must be specified if using this option. |
bSpline Order | The bSpline Order defines the degree of smoothing you wish to apply. |
Procedure
1. Select a feature layer with line features available.
2. Select one or more lines.
3. Select the Simplify/Smooth command.
The Simplify/Smooth dialog box is displayed.
4. Select Simplify and/or Smooth.
5. Set any necessary options.
6. Click OK.
The selected line is smoothed/simplified according to the settings defined.
Example
Below is a group of contours that have been smoothed using a bSpline Order of 3.
