Related to the question line below. How do I make the arrow point to the line correctly ?
This code did not work :
with_variable('myvalue',line_interpolate_angle(geometry:=intersection(buffer(geometry:=$geometry, distance:=50, segments:=3),overlay_nearest(layer:='railways', expression:=$geometry)[0]), distance:=50),if(@myvalue < 180,@myvalue+90,@myvalue-90))
Rotating point layer according to line layer in QGIS
For the rotation of the arrow marker, use this expression on the point layer and replace line in line 4 with the name of the line layer.
Explanation: for each point, calculate the azimuth (angle) with the function azimuth() from the initial point ($geometry) to the closest point on the line (to get the line: use overlay_nearest()) with the function closest_point(). Convert radians to degrees with degrees().
degrees(
azimuth(
$geometry,
closest_point( overlay_nearest ( 'line', $geometry)[0],
$geometry
)
)
)
Dotted line for visualization purpose only:
