"Extract within distance" algorithms
These algorithms allow users to select or extract features from one
layer which are within a certain distance of features from another
reference layer.
The distance checking is heavily optimised, using spatial indices
to restrict the number of features retrieved, and also automatically
handing the check off to the database server for postgis layers.
The distance parameter can also be data-defined.
Sponsored by QTIBIA Engineering
Allows users to select a list of fields to keep, and all other fields
will be dropped from the layer. Helps with making flexible models where
input datasets may have a range of different fields and you need to drop
all but a certain subset of these
This algorithm calculates the rotation required to align point features
with their nearest feature from another reference layer. A new field is
added to the output layer which is filled with the angle (in degrees,
clockwise) to the nearest reference feature.
Optionally, the output layer's symbology can be set to automatically
use the calculated rotation field to rotate marker symbols.
If desired, a maximum distance to use when aligning points can be set,
to avoid aligning isolated points to distant features.
Designed for use cases like aligning building point symbols to follow
the nearest road direction!
Offers the same functionality as the Random points inside polygons
algorithm, and in addition it includes (possible to opt-out) the attributes
from the containing polygon and the ability to specify a seed for the random
number generator.
Could replace the Python algorithm Random points inside polygons, but
this C++ implementation only supports "Points count" ("number of points
for each feature") directly, while "Points density" is supported by allowing the
point count to be data defined (using the polygon area to calculate the
number of points).
