Related to my previous question: Colouring contour lines differently when they are inside polygons of another layer I would like to create a new layer based upon the result of the geometry generator linestring/multilinestring expression:
intersection(collect($geometry),aggregate('NZ_Snow_Polygons__Topo__1_50k__72b39e76_c3e8_4878_a811_8e3dc5ade0d4','collect',$geometry,intersects($geometry,geometry(@parent))))
That as the expression for a linestring/multilinestring geometry generator works but is very very slow. Hence I want to use the result for a new static layer and render like the contour layer - or at least that is my goal.
I've tried "Vector Selection", "Select by expression" with the expectation I can save the selection as a layer, but the expression above runs for over 24 hrs at which point my patience is exhausted and I kill it.
What is the correct way to create a new layer that is the collection of contour lines sections where they intersect the snow polygons? i.e. Gives me the results I get with the geometry generator with none of the constant regeneration and slowness.
Geometry by expressionfrom the processing toolbox? – ahmadhanb Sep 10 '20 at 23:47