FME Transformers: 2024.1
FME Transformers: 2024.1
2DArcReplacer
Replaces or creates feature geometry with a 2D arc as defined in parameters for center point, radii, angles, and rotation.
Typical Uses

Creating arc geometry from attribute values or user parameters

Replacing point geometry with arcs defined by values
How does it work?
The 2DArcReplacer receives features of any kind and replaces their geometry with arcs as defined in parameters.
The parameters describe Arc By Center Point geometry with the following:

Center X and Y coordinates

Primary and Secondary Radius in ground units

Start Angle and Sweep Angle in degrees

Rotation in degrees
Values may be entered or provided through attribute values, expressions, or user parameters.
If the Center X and Y coordinates are left blank, the first coordinate of the feature’s existing geometry will be used. If the feature has no geometry, the center is set to 0,0.
For more information on arc geometry and types, see Arc.
Examples
Example: Replacing points with arcs
In this example, we have a set of points and want to replace them with arcs.
The features are routed into a 2DArcReplacer.
In the parameters dialog, values are entered for radii and angles, but the Center X and Y parameters are left blank.
The points have been replaced by arcs as specified.
Usage Notes

If the arc values are unknown and need to be calculated from a line feature, consider using the Curvefitter or ArcEstimator.

The Creator can create alternate arc types Arc By Bulge and Arc By 3 Points.
Creating and Modifying Arcs, Circles, and Ellipses
These transformers work with arcs in a variety of ways.
Arc Transformers Comparison

Function 
Geometry Out 
Z Coordinates 

Creates one or more new features with arc geometry (when Geometry Object is an arc type). 
Arc by center point Arc by center point with ends Arc by 3 points Arc by bulge Ellipse (Arc by center point) 
Supported 

Replaces any existing feature’s geometry with a 2D arc. 
Arc by center point 
No 

Replaces any existing feature’s geometry with a 3D arc. 
Arc by center point 
Yes, at center point 

Replaces an existing feature’s geometry with a 2D ellipse or circle (closed arc). 
Ellipse (Arc by center point) 
No 

Modifies an existing arc or converts a point to an arc. 
Arc by center point Arc by center point with ends Arc by 3 points 
Supported, at center and/or ends 

Modifies an existing ellipse (closed arc) or converts a point to an ellipse. 
Ellipse (Arc by center point) 
Supported, at center point 

Extracts the property values that describe an arc’s geometry and stores them as attributes. 
Arc by center point Arc by center point with ends Arc by 3 points Arc by bulge 
Supported 

Extracts the property values that describe an ellipse’s geometry and stores them as attributes. 
Ellipse (Arc by center point) 
Supported 

Converts arcs and ellipses to lines or polygons by interpolating points along the arc. 
Path Line Area 
Supported 

Replaces geometry with an arc described by the first, middle, and last vertices of the input feature. 
Arc by 3 points 
Supported 

Replaces lines or polygons with an optimal combination of line and arc segments, creating smooth curving lines. 
Path Area Arc by bulge Line 
Supported 

Reduces point density on lines or polygons, fitting arcs where possible (When using Algorithm > Douglas With Arc Fitting (Generalize) ). 
Path Area Arc by 3 points Line 
Supported 

Either replaces an existing feature’s geometry with circle that contains all of its vertices or extracts the circle property values into attributes. 
Ellipse (Arc by center point) 
No 
Configuration
Input Ports
Input
This transformer accepts any feature.
Output Ports
Parameters
General
Center X 
Specify the X coordinate of the arc’s origin. If blank, the X coordinate of the first vertex of the input feature’s geometry will be used. If that feature has no geometry, the value will be zero (0). 
Center Y 
Specify the Y coordinate of the arc’s origin. If blank, the Y coordinate of the first vertex of the input feature’s geometry will be used. If that feature has no geometry, the value will be zero (0). 
Primary Radius 
Specify the primary radius of the arc in ground units. Note that the primary radius need not be larger than the secondary, however, the rotation angle is always measured from the x axis to the primary axis. For a circular arc, set both the primary and secondary radius to the same value. 
Secondary Radius 
Specify the secondary radius of the arc in ground units. 
Start Angle 
Specify the starting angle of the arc, in degrees counterclockwise from the primary axis (horizontal plus or minus rotation). 
Sweep Angle 
Specify the sweep angle in degrees, which controls the duration of the arc. Positive sweep angles, run counterclockwise beginning at the start angle and ending at the sum of the start and sweep angles. Negative sweep angles run clockwise. 
Rotation 
Specify the rotation in degrees of the primary axis from horizontal (if any). 
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.
How to Set Parameter Values
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.
Using the Text Editor
The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.
Using the Arithmetic Editor
The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.
Conditional Values
Set values depending on one or more test conditions that either pass or fail.
Parameter Condition Definition Dialog
Content
Expressions and strings can include a number of functions, characters, parameters, and more.
When setting values  whether entered directly in a parameter or constructed using one of the editors  strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.
Content Types
These functions manipulate and format strings.  
Special Characters 
A set of control characters is available in the Text Editor. 
Math functions are available in both editors.  
Date/Time Functions  Date and time functions are available in the Text Editor. 
These operators are available in the Arithmetic Editor.  
These return primarily featurespecific values.  
FME and workspacespecific parameters may be used.  
Creating and Modifying User Parameters  Create your own editable parameters. 
Dialog Options  Tables
Table Tools
Transformers with tablestyle parameters have additional tools for populating and manipulating values.
Row Reordering

Enabled once you have clicked on a row item. Choices include:

Cut, Copy, and Paste

Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers. 
Filter

Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer  it does not alter which attributes are output. 
Import

Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. 
Reset/Refresh

Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers. 
Note: Not all tools are available in all transformers.
For more information, see Transformer Parameter Menu Options.
Reference
Processing Behavior 

Feature Holding 
No 
Dependencies  None 
Aliases  
History 
FME Community
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Examples may contain information licensed under the Open Government Licence – Vancouver, Open Government Licence  British Columbia, and/or Open Government Licence – Canada.