Generalize a feature

In the Modify Features pane, Generalize contains several methods that reduce the complexity of a line or a polygon feature while retaining its basic shape. They can help you simplify features for display at smaller scales or standardize a dataset to a more uniform scale resolution.

You can turn on map topology and preserve connectivity among features that share coincident geometry, or turn off map topology and select the features you want to generalize together and create coincident boundary segments.

Simplify a feature

Simplifying a feature changes curved segments to series of line segments. Existing line segments remain unchanged. The final shape is generalized within the maximum allowable offset setting you specify in the pane.

Alternatively, you can use a geoprocessing tool. To learn more, see Generalize.

1. On the Edit tab, in the Manage Edits group, click the Topology drop-down arrow and choose one of the following settings.
   • Map Topology —Modifies adjacent features and maintains connectivity among all shared boundaries.
   • No Topology —Modifies only the selected features and creates coincident boundary segments between them.
2. On the Edit tab, in the Features group, click Modify .

   The Modify Features pane appears.

3. Expand Reshape and click Generalize .

   The tool opens in the pane.

4. In the pane, click Active Select , and select overlapping polyline features on the same layer.

   The selection appears as a list in the pane.

5. To refine your selection, right-click a feature in the list and use the following commands on the context menu:
   • Flash —Flashes the selected features in the map.
   • Zoom To —Zooms the view to the selected features.
   • Pan To —Pans the view to the selected features.
   • Only Select This —Removes all other features from the selection.
   • Unselect —Removes the feature from the selection.
6. Click Simplify.
7. Confirm Show Preview is checked.
8. In the Maximum Allowable Offset text box, type the distance in map units within which you want the feature generalized. Notice how changing this value produces different results.

   Note:

   When the offset is greater than zero (0), curved segments are simplified along the curve using the Douglas-Peucker simplification algorithm.

9. Click Generalize.

Smooth a feature

Smoothing a feature changes straight edges and angular corners to Bézier curves. The final shape is simplified and smoothed within the maximum allowable offset setting you specify in the pane.

Alternatively, you can use a geoprocessing tool. To learn more, see Smooth Line and Smooth Polygon.

1. On the Edit tab, in the Manage Edits group, click the Topology drop-down arrow and choose one of the following settings.
   • Map Topology —Modifies adjacent features and maintains connectivity among all shared boundaries.
   • No Topology —Modifies only the selected features and creates coincident boundary segments between them.
2. On the Edit tab, in the Features group, click Modify .

   The Modify Features pane appears.

3. Expand Reshape and click Generalize .

   The tool opens in the pane.

4. In the pane, click Active Select , and select overlapping polyline features on the same layer.

   The selection appears as a list in the pane.

5. To refine your selection, right-click a feature in the list and use the following commands on the context menu:
   • Flash —Flashes the selected features in the map.
   • Zoom To —Zooms the view to the selected features.
   • Pan To —Pans the view to the selected features.
   • Only Select This —Removes all other features from the selection.
   • Unselect —Removes the feature from the selection.
6. Click Smooth.
7. Confirm Show Preview is checked.
8. In the Maximum Allowable Offset text box, type the distance in map units within which you want the feature simplified. Notice how changing the method and value produces different results.
   • When the offset is set to zero (0), each segment is converted to a Bézier curve.
   • When the offset is greater than zero (0), the feature is first generalized by the Douglas-Peucker simplification algorithm. Bezier curves are then created for each remaining segment with complementary tangents that create smooth transitions between segments.
9. Click Generalize.

Densify a feature

Densifying a feature inserts vertices at constant intervals and changes curved segments to a series of line segments. You can insert segments that approximate the entire feature or modify only the curved segments within a maximum offset distance or deflection angle.

Alternatively, you can use a geoprocessing tool. To learn more, see Densify.

1. On the Edit tab, in the Manage Edits group, click the Topology drop-down arrow and choose one of the following settings.
   • Map Topology —Modifies adjacent features and maintains connectivity among all shared boundaries.
   • No Topology —Modifies only the selected features and creates coincident boundary segments between them.
2. On the Edit tab, in the Features group, click Modify .

   The Modify Features pane appears.

3. Expand Reshape and click Generalize .

   The tool opens in the pane.

4. In the pane, click Active Select and select overlapping polyline features on the same layer.

   The selection appears as a list in the pane.

5. To refine your selection, right-click a feature in the list and use the following commands on the context menu:
   • Flash —Flashes the selected features in the map.
   • Zoom To —Zooms the view to the selected features.
   • Pan To —Pans the view to the selected features.
   • Only Select This —Removes all other features from the selection.
   • Unselect —Removes the feature from the selection.
6. Click Densify.
7. Confirm Show Preview is checked.
8. Choose how segments are densified. Notice how changing the method and value produces different results.
   • Distance—Replaces the entire feature with line segments at constant intervals whose lengths do not exceed the specified linear distance.
     • If the distance is zero (0), no vertices are added.
     • If the distance is negative, the system default value is applied.
   • Offset—Replaces curves with line segments whose vertices do not extend beyond the specified maximum offset.
   • Angle—Replaces curves with line segments whose deflection angles do not exceed the specified angle.
9. Click Generalize.