Performs an overlay of points on lines. Each input line is split at its closest place to any point within the specified point tolerance.
The Group By parameter allows you to choose a series of attributes that must match on the features before the attributes will be merged. This can be used to ensure that the overlay occurs only on certain groups of 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.
Yes: 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.
No: This is the default behavior. Processing will only occur in this transformer once all input is present.
The Overlap Count Attribute added to output linear features holds the number of point features that were near to it. The Overlap Count Attribute added to output point features holds the number of linear features that the point was near to.
The Point Tolerance value is compared to the distance from the lines to the points, and the lines will be segmented if the distance is less than or equal to the Point Tolerance value. When such a match occurs, the attributes of the segmented lines are merged with the points and the attributes of the points are merged with the lines.
If attributes on the incoming and original feature share the same name, but are not geometry attributes that start with fme_, then they are deemed conflicted.
Note: On the PointOnLineOverlayer, Attribute Accumulation applies to the measures on a point in a similar way to how it applies to the attributes on a feature.
If measures on the point and line share the same name, then they are deemed conflicted.
The resolution of conflicted measures on points occurs in the same manner as the resolution of conflicted attributes on features. It is resolved according to the Accumulation Mode and Conflict Resolution values.
Merge Incoming: The original feature will retain all of its own un-conflicted attributes, and will additionally acquire any un-conflicted attributes that the incoming feature has. This mode will handle conflicted attributes based on the Conflict Resolution parameter.
Prefix Incoming: The original feature will retain all of its own attributes. In addition, the original will acquire attributes reflecting the incoming feature’s attributes, with the name prefixed with the Prefix parameter.
Only Use Incoming: The original feature will have all of its attributes removed, except geometry attributes that start with fme_. Then, all of the attributes from one (arbitrary) incoming feature will be placed onto the original.
Use Original: If a conflict occurs, the original values will be maintained.
Use Incoming: If a conflict occurs, the values of the incoming will be transferred onto the original.
If the Accumulation Mode parameter is set to Prefix Incoming, this value will prefix attributes and measures that are being added to the original feature from the incoming feature.
If the optional List Name is supplied, the attributes of each point used to segment an output line are added to that line's list, and the attributes of each line that a point segmented are added to that point's list.
Note: Attribute lists are not accessible from the output schema in Workbench unless they are first processed using a transformer that operates on them, such as ListExploder or ListConcatenator. All attribute list transformers are displayed in the Contents pane of the Transformer Help under Lists. Alternatively, AttributeExposer can be used.
- Each resulting point receives the attributes of the point(s) it was paired with. When attributes are merged between features, existing attributes are not replaced. Therefore if the points and areas being overlaid have attributes with the same name, then the values will not be transferred from one to the other. You can avoid this problem by renaming (AttributeRenamer), prefixing (AttributeExpressionRenamer), or removing (AttributeRemover) attributes to avoid name collisions.
- Note that intersections between linear features are not computed.
- Aggregates are not supported by this transformer.
- Note that where Point geometries are expected as input, PointCloud geometries are not supported.
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.
FME Licensing Level
FME Professional edition and above
Search FME Knowledge Center
Search for samples and information about this transformer on the FME Knowledge Center.