Performs warping operations on the spatial coordinates of features. It is used to adjust a set of observed input features according to a spatial transform defined by a set of control vectors. This transformer computes an affine (scale, rotation, and offset) transformation based on Control vector features and applies this transformation to the Observed features to generate output, and produces good corrections when the entire set of Observed data requires a single transformation.

Each Control feature represents a control vector (a 2-point line feature) whose start point is at some location in the original Observed data space, and whose end point is at the corresponding location in the desired output data space. Each control vector represents the correction required to go from the observed vertex to the desired vertex, in terms of direction and distance. Control vectors with only one point are interpreted as a requirement that this location not change from the observed dataset to the reference dataset. This is often referred to as a tie point.

Control vectors can be stored in a dataset of any format and read into FME, or generated directly in an FME workspace, which is often the case when the vectors are not known in advance and must be generated from incoming data.

Input Ports

Two sets of features must be routed into this transformer.

Output Ports


Group Processing

Usage Notes

  • The RubberSheeter transformer provides similar functionality but applies a different transformation to each Observed vertex, depending on its distance to nearby Control vectors. This makes the RubberSheeter more appropriate for cases when the distortions in the data are not constant.
  • Please also see the Affiner, which performs an affine transformation on the coordinates of the feature.

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

The FME Community is the place for demos, how-tos, articles, FAQs, and more. Get answers to your questions, learn from other users, and suggest, vote, and comment on new features.

Search for samples and information about this transformer on the FME Community.


Keywords: pointcloud