Geometry generator style hacks in QGIS

In QGIS you can use expressions to change the shapes and properties of your features. In particular, you can use geometry generator expressions to do all sorts of interesting things. But it's much easier to understand if you just see how it works, so that's why I've put together this longer video.
Here's the file used in the video (it's the .gpkg at the link below, but the .shp or .geojson will work just as well) and you can add it to your own QGIS and follow along if you want to.
automaticknowl...
Some of the expressions used:
buffer(minimal_circle($geometry,500),-4000)
--
buffer($geometry,rand(-10000,-1000))
--
CASE
WHEN "Country" = 'Scotland' THEN
buffer(minimal_circle($geometry,500),-4000)
ELSE
$geometry
END
--
rotate(buffer(
make_triangle(
make_point(x_min($geometry),y_min($geometry)),
make_point(x_max($geometry),y_min($geometry)),
make_point( (x_min( $geometry)+x_max($geometry))/2,y_max($geometry))
),
-2000),
rand(-25,25))
See my intro and intermediate QGIS courses for more: www.udemy.com/...