{ "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"] }