Displacer
Solves proximity conflicts between features using a variant of the Nickerson displacement algorithm. This transformer is usually used after generalization.
Input and Output Ports
The features routed into the transformer through the Base port are geometrically frozen (cannot move).
The features routed in through the Candidate port are compared against the Base feature(s), displaced as necessary, and exit through the Displaced port. If no displacement occurred, they exit through the Untouched port.
Each comparison/displacement is independent of the others.
Base features with geometries other than point, curve or area (polygon or ellipse or donut) will exit through the InvalidBase port. Candidate features with geometries other than point, curve or simple area (polygon or ellipse) will exit through the InvalidCandidate port.
The ExtraBase port holds extra Base features as described in the Base Type parameter below.
Parameters
Transformer
You can use this option to narrow down which candidate features to compare with which base features.
Note: How parallel processing works with FME: see About Parallel Processing for detailed information.
This parameter determines whether or not the transformer should perform the work across parallel processes. If it is enabled, a process will be launched for each group specified by the Group By parameter.
Parallel Processing Levels
For example, on a quad-core machine, minimal parallelism will result in two simultaneous FME processes. Extreme parallelism on an 8-core machine would result in 16 simultaneous processes.
You can experiment with this feature and view the information in the Windows Task Manager and the Workbench Log window.
No: This is the default behavior. Processing will only occur in this transformer once all input is present.
By Group: This transformer will process input groups in order. Changes on the value of the Group By parameter on the input stream will trigger batch processing on the currently accumulating group. This will improve overall speed if groups are large/complex, but could cause undesired behavior if input groups are not truly ordered.
Parameters
Specifies how much the displacement at one point in the candidate feature's geometry should affect the neighboring points. A lower value means that the candidate geometry can be deformed easily, while a higher value means that it will try its best to keep its original shape.
The Minimum Separating Distance parameter specifies the minimum separating distance between the candidate feature's geometry and the base feature's geometry after displacement.
The Displace Endpoints parameter specifies whether or not to displace the endpoints of candidate features whose geometries are unclosed lines.
The Base Type parameter specifies whether only a single Base feature will be used, or whether all Base features will be used. If Bases First is selected, then the transformer assumes that all Base features will enter the transformer before any Candidate features. Any further Base features that arrive after the first Candidate will be output through the ExtraBase port. The same goes for any Base features after the first when in Single Base mode.
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.
Transformer Categories
Related Transformers
FME Licensing Level
FME Professional edition and above
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Tags Keywords: displacement resolve conflict generalization Nickerson generalize NickersonDisplacer