LineJoiner

From Fmepedia

LineJoiner is a Workbench Transformer.

A LineJoiner takes non-intersecting lines and connects them into longer lines whenever doing so does not remove a significant node. Any nodes with only two lines connecting to them (sometimes called psuedonodes) are removed. Lines remain broken at points where three or more converge. Features with invalid geometries are sent to the INVALID output. An Intersector can be used to clean up data before it's going into a LineJoiner.

Break Across Groups indicates how groups are considered:

• If yes, the transformer will consider all nodes from all groups of features when deciding on topologically significant points;
• If no, each group will be considered separately.

Preserve Original Orientation controls whether or not lines can be reversed in order to create longer lines. If the direction of the lines is significant to your application, then choose yes.

Break Loops indicates whether any resulting (or input) closed rings should ever be broken into two segements:

• If you choose yes and the input data contained a set of lines that formed a ring and did not interact with any other lines, no closed ring will be formed and the two lines will be returned, broken at two arbitrary end vertices of the original input.
• If you choose no, then if a set of lines independent from any other set of lines would form a ring, they will be connected into a single linear feature whose start and end point is the same. The feature will be considered as having a geometry type of line and not polygon, however, the GeometryCoercer could be used to promote its geometry type to polygon.

The Group By list of attributes separates the input data into sets which are considered independently when the node removal is done. Only attributes that are listed in the Group By list will be passed to subsequent transformers – all other attributes are removed.