Takes a set of topologically connected linework and creates topologically correct polygon features where the linework forms closed shapes.

Input Ports

Output Ports


Group Processing


Create Donuts

Attribute Accumulation

Generate List

When enabled, adds a list attribute to the output features, containing an element for each input feature which contributed to that geometry, in order of appearance.

This parameter can also be used to preserve attributes from input features.

Snapping Pre-Processing Parameters


The example below illustrates a set of topologically connected linework on the left and the output of the AreaBuilder transformer on the right. In the output, the topologically correct polygons are highlighted in blue where the linework formed closed shapes, while the lines that did not close are shown in red.

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.

FME Community

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Keywords: CAD fenceline island ring PolygonBuilder Polygonizer