FME Transformers: 2024.1

Categories
Coordinates
Geometries
Related Transformers
3DAffiner
Affiner
AffineWarper
LocalCoordinateSystemSetter
Offsetter
RasterGCPSetter
RasterGeoreferencer
Rotator
Scaler

# RubberSheeter

Variably adjusts vector feature coordinates based on their proximity to control vectors indicating current and desired positions.

### Typical Uses

• Applying positional corrections when the modifications are not consistent across the dataset.

## How does it work?

The RubberSheeter receives two types of features - those to be adjusted (Observed) and those that describe how that adjustment is done (Control vectors and Constraints).

Observed features can have any type of vector geometry.

Most Control vectors have two points. The start point is located somewhere in the Observed features’ space, and the end point is the desired new location of that point.

A Control vector with only one point indicates that a location should not move - often called a tie point.

Each vertex is modified differently, depending on how close it is to nearby Control vectors (using inverse distance weighting). Only Control vectors that start within the specified Max Distance are used to calculate the new position. This can result in part of a feature being transformed and part of it remaining as is.

Constraints are optional. These lines are treated as boundaries, across which Control vectors will have no influence. If the line of sight from a point on an Observed feature to the starting point of a Control vector crosses a Constraint line, that Control vector will not affect the point in question. If the line of sight touches the end of a Constraint line, or either the Control vector or Observed point is actually located on the Constraint line, the Control vector will influence the observed point.

The modified Observed features are output via the Corrected port. Control vectors and Constraints are discarded.

## Usage Notes

• The AffineWarper transformer provides similar functionality but computes an affine transformation (scale, rotation, and offset) based on Control vector features and applies this transformation to the Observed features. This is more appropriate for cases when the entire set of Observed data requires a single, consistent transformation.

• Raster geometry is not supported.

## Editing Transformer Parameters

Transformer parameters can be set by directly entering values, using expressions, or referencing other elements in the workspace such as attribute values or user parameters. Various editors and context menus are available to assist. To see what is available, click beside the applicable parameter.

## Reference

 Processing Behavior Feature Holding Yes Dependencies None Aliases History

## 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 all results about the RubberSheeter on the FME Community.

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