Performs a line-on-line overlay in which all input lines are intersected against each other and resultant line features are created and output. Intersection points are turned into point features that can contain the merged list of attributes of the original intersected lines.

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Typical Uses

  • Splitting lines at intersections
  • Preparing line features for network topology creation

How does it work?

The LineOnLineOverlayer takes in line features and compares them to each other. Where they intersect, the lines are split, each segment retaining its original attributes and receiving attributes from the intersecting line.

Point features are created at the intersections, and may receive attributes from the intersecting lines.

Optionally, a list attribute may be created to receive attributes (for both lines and intersection points), that will store attributes from multiple features. The intersection point features will also include line direction and angle for each intersecting line.

Aggregates can either be deaggregated before processing or rejected.


Usage Notes

  • When choosing to output only one segment for each collinear group (equivalent lines or points in the same position), it may be difficult to predict which of the "original" geometries and attributes are preserved. In general, the features that arrive at the transformer FIRST will be the ones that form the separate segments. Use the FeatureHolder or Sorter transformers to change the sequence of features if this is important.
  • This transformer will preserve measures, based on the rules for the order of features described above.

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



FME Community

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