Performs a line-on-area overlay, either splitting lines where they intersect area boundaries or subdividing areas where split by lines. Attributes may be shared between related lines and areas (spatial join).

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Typical Uses

  • Splitting lines where they cross the boundary of a polygon
  • Splitting polygons where crossed by lines
  • Identifying which polygons contain or intersect lines
  • Identifying lines that intersect or fall within areas

How does it work?

The LineOnAreaOverlayer compares lines and polygons, splitting geometry where they intersect.

It has two modes:

  • Split Lines With Areas: Lines are split where they intersect with a polygon boundary. Each resulting piece may receive the attributes of the area(s) it is contained in, and each containing area may receive the attributes of the line(s) that either fall within or intersect it (a spatial join). Features also receive a count of the number of overlaps encountered.

  • Split Areas With Lines: Areas are subdivided where they are split by lines or sets of lines. Only lines that split areas are considered for attribute merging and overlap counts.

Aggregates can either be deaggregated before processing or rejected.


Usage Notes

Choosing a Spatial Transformer

Many transformers can assess spatial relationships and perform spatial joins - analyzing topology, merging attributes, and sometimes modifying geometry. Generally, choosing the one that is most specific to the task you need to accomplish will provide the optimal performance results. If there is more than one way to do it (which is frequently the case), time spent on performance testing alternate methods may be worthwhile.

To correctly analyze spatial relationships, all features should be in the same coordinate system. The Reprojector may be useful for reprojecting features within the workspace.


Input Ports

Output Ports


Editing Transformer Parameters

Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.

Defining Values

There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.

Dialog Options - Tables

Transformers with table-style parameters have additional tools for populating and manipulating values.


Processing Behavior


Feature Holding



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Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.