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how to get cross line on polygon?

S
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i have lines and i have polygon

my question that i would like to find which line intersects with polygon and which lines crosses with polygon

so i have transformed polygon to lines by geometry coercer then i used spatial filter ,predicate crosses

and another time i used spatial filter with predicate intersect

 

but i have found that the output in passed port even if i have chosen predicate cross or intersect ,i get this line in output

 

why did this line appear when i choose predicate intersect ,because no intersection point between line and polygon .

 

i would like to have it only when i use predicate cross .

i hope someone has idea for me

 

 

FME 2020question

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Best answer by geomancer 13 July 2022, 11:44

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geomancer
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You misinterpret 'Intersect'. Objects intersect when they are 'Not Disjoint', see Spatial Relations Defined. So when two objects cross, they also intersect (but not necessarily the other way around).

Also you don't have to coerce your polygons into polylines to test for intersection (or crossing).

S
Badge +3

You misinterpret 'Intersect'. Objects intersect when they are 'Not Disjoint', see Spatial Relations Defined. So when two objects cross, they also intersect (but not necessarily the other way around).

Also you don't have to coerce your polygons into polylines to test for intersection (or crossing).

why did they consider as intersect object also ,if they have not intersection in point between both of them ?

geomancer
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Userlevel 4
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Now if you want to test for vertices in common, you can do a SpatialFilter on the vertices, like this.

Common_Vertices

geomancer
Rank
Userlevel 4
Badge +35

You misinterpret 'Intersect'. Objects intersect when they are 'Not Disjoint', see Spatial Relations Defined. So when two objects cross, they also intersect (but not necessarily the other way around).

Also you don't have to coerce your polygons into polylines to test for intersection (or crossing).

When objects are not disjoint, they intersect. Look at the definitions in Spatial Relations Defined.

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