Function Description

The Extract Centerline from Polygon refers to the centerline of all face objects in the Extract Surface Data set, and the result is saved as Line Dataset, which is generally used to extract the centerline of the road surface.

Function entrance

• Data tab-> Data Processing-> Vector-> Extract Centerline from Polygon.
• Toolbox, Data Processing, Vector, Extract Centerline from Polygon.

Parameter Description

Set the following parameters in the Extract Centerline from Polygon dialog:

• Source Data: Select Datasource and Region Dataset to Extract Center Line.
• Result Data: Set the Datasource and Dataset Name stored in the Result Data. The Result Dataset is named "result _ RegionToCenterLine" "by default.
• Set the maximum and minimum widths of extraction at

  Parameter Settings:

  • Max Width: The maximum width value (greater than 0) between the boundary lines of the face object requiring Extract Center Line. When the distance between boundary lines of face objects is greater than maximum width, extract the boundary line. The default value is 30. The unit is the same as Source Dataset. The maximum width should be greater than minimum width. The user can measure the maximum width of the face object by clicking the button on the right. It is recommended that the maximum width set by the user is slightly greater than actual measured distance, so that the extracted results will be more accurate
  • Minimum width: The minimum width between the boundary lines of the face objects to be Extract Center Line (Greater than or equal to 0). When the distance between the boundary lines of the face objects is less than minimum width, the center line at this point will not be extracted. The default value is 0. The units are the same as the Source Dataset, and the minimum width should be less than maximum width.
  Hint:

  The centerline of a

  face object is extracted when its width is between the maximum and minimum widths; it is not Extract Center Line when its width is less than minimum width; and it is extracted when its width is greater than maximum width.

  After

  setting the Result Dataset, you can execute the Extract Center Line operation. The result is shown in the following figure. In the Result Dataset attribute table, the Attributes of the source surface object will be retained for the user to view and compare.

  

Caution:

The setting of the maximum and minimum width between the boundary lines of the
• face object will affect the accuracy of the Result Data, and the user needs to accurately input the maximum and minimum width values.
• For the more complex intersections in the road, such as overpasses, five forks and six forks, the extraction results may not be ideal.

Related topics

Extract Centerline from Two Lines

Face extraction trunk line