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Intersector
Category: Geometric Operators
Computes intersections between all input features, breaking lines and
polygons wherever an intersection occurs. In addition, all overlapping
segments are reduced to one segment before being output.
Note: If the Geometry Handling advanced setting is set to Rich" in
the workspace, arcs and ellipses are produced when intersecting arcs
and ellipses; otherwise, the results are geometries of type fme_line.
The Separate Collinear Segments option causes overlapping segments not
to be merged into a single segment: one copy is output for each
original feature sharing the segment.
When a coverage of polygons is input, the set of topologically
significant lines which form their boundaries is output.
Duplicate Nodes at Each Elevation
The creation of nodes can be calculated in 3D, if requested.
Constructing nodes in 3D would mean that line segments would only
share a node if they shared the same Z value at the point they
intersected. Constructing nodes in 2D would mean that all intersecting
segments would share a common node, regardless of their respective Z
values. Consider, for example, a situation where two lines (which
crossed) represented roads, where one road was an overpass above the
other road. Suppose these two lines had differing elevations. If you
constructed nodes in 3D, these two roads would not be linked to the
same node where they crossed. Two nodes would be produced at the
crossing point - each one with a different Z value. If you constructed
nodes in 2D, these lines would both link to a common node, which would
be present at the location where they crossed. In either the 2D or 3D
case, the full dimensionality of the input is preserved in the output
- 3D features are never converted to 2D. The 2D or 3D choice only
indicates how the nodes are created and which lines are linked to
them; it does not affect the dimension of the features that are
output.
If the Duplicate Nodes at Each Elevation parameter is set to Yes, then
whenever 3D lines intersect at differing heights, two 2D nodes will be
output via the NODE port. Each node will have the same x and y
coordinates, but a different node number.
If the Duplicate Nodes at Each Elevation parameter is set to No, then
whenever 3D lines intersect at differing heights, a single 2D node is
output at the intersection point.
Overlap Count Attribute
The Overlap Count Attribute parameter names an attribute that will be
added by the transformer, containing the number of input lines that
overlapped atop of the output segment.
Segment Count Attribute
The Segment Count Attribute parameter, if specified, names an
attribute that will be added by the transformer, containing the number
of segments into which the segments original feature was divided.
List Name
If the optional list name is supplied, a list of all the attributes of
each lines which overlapped an output segment is made. This allows
later inspection of overlapping segment attributes.
Separate Collinear Segments
This option causes overlapping segments not to be merged into a single
segment - one copy is output for each original feature sharing the
segment.
Any line segments that are collinear are not merged together; instead,
one copy is output for each original feature which shared that
segment. Each such segment will have the respective original features
attributes as its main attributes, and attributes from all other
collinear features will be added as a list attribute, if the list name
was supplied.
Split Self-Intersecting Features
If the Split Self-Intersecting Features parameter is set to Yes,
self-intersections in the input features are removed by splitting the
feature.
Example
[intersector.gif]
FME Function or Factory Used
IntersectionFactory
[1]View a task scenario that uses Intersector.
References
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