Line Intersections

Draft: written, not yet checked by a person Operation · line-intersections

A point wherever a line in one layer crosses a line in another.

Pitfall. Lines that overlap along a stretch, rather than crossing, give a line or nothing, depending on the engine.

Pitfall. Engines differ on whether a point where two lines touch end to end counts as a crossing.

About this operation
Also called	Intersect (point output), crossing points, Line intersections, line crossings
Group	`vector/overlay`
Checks	`crs.agreement`
Pitfalls	2 listed above
Columbus tool	Not stated
Notes	Not stated
Status	active
Broader	Not stated
Narrower	Not stated
Related	`intersect`

Parameters

Not stated

Direction	Name	Type	Geometry	Note
Input	`a`	vector	line	Not stated
Input	`b`	vector	line	Not stated
Output	`output`	vector	point	Not stated

Engine	Tool	Parameters	Differences
`qgis`	`native:lineintersections`	`a` → `INPUT` `b` → `INTERSECT` `output` → `OUTPUT`	INPUT_FIELDS and INTERSECT_FIELDS choose which attributes the points carry.
`turf-js`	`turf.lineIntersect`	`a` → `line1` `b` → `line2`	options.removeDuplicates and ignoreSelfIntersections control repeated and self-crossing points. Turf works on GeoJSON in longitude/latitude (WGS 84); data in another CRS must be reprojected first.
`whiteboxtools`	`LineIntersections`	`a` → `input1` `b` → `input2` `output` → `output`	Also takes polygons, using their outlines.