QGIS/resources/function_help/json/smooth

{
  "name": "smooth",
  "type": "function",
  "groups": ["GeometryGroup"],
  "description": "Smooths a geometry by adding extra nodes which round off corners in the geometry. If input geometries contain Z or M values, these will also be smoothed and the output geometry will retain the same dimensionality as the input geometry.",
  "arguments": [{
    "arg": "geometry",
    "description": "a geometry"
  }, {
    "arg": "iterations",
    "optional": true,
    "default": "1",
    "description": "number of smoothing iterations to apply. Larger numbers result in smoother but more complex geometries."
  }, {
    "arg": "offset",
    "optional": true,
    "default": "0.25",
    "description": "value between 0 and 0.5 which controls how tightly the smoothed geometry follow the original geometry. Smaller values result in a tighter smoothing, larger values result in looser smoothing."
  }, {
    "arg": "min_length",
    "optional": true,
    "default": "-1",
    "description": "minimum length of segments to apply smoothing to. This parameter can be used to avoid placing excessive additional nodes in shorter segments of the geometry."
  }, {
    "arg": "max_angle",
    "optional": true,
    "default": "180",
    "description": "maximum angle at node for smoothing to be applied (0-180). By lowering the maximum angle intentionally sharp corners in the geometry can be preserved. For instance, a value of 80 degrees will retain right angles in the geometry."
  }],
  "examples": [{
    "expression": "geom_to_wkt(smooth(geometry:=geom_from_wkt('LineString(0 0, 5 0, 5 5)'),iterations:=1,offset:=0.2,min_length:=-1,max_angle:=180))",
    "returns": "'LineString (0 0, 4 0, 5 1, 5 5)'"
  }],
  "tags": ["adding", "corners", "smoothed", "dimensionality", "round", "output", "contain", "input", "retain", "extra", "smooths", "nodes", "values", "same"]
}