QGIS/resources/function_help/json/buffer

{
  "name": "buffer",
  "type": "function",
  "groups": ["GeometryGroup"],
  "description": "Returns a geometry that represents all points whose distance from this geometry is less than or equal to distance. Calculations are in the Spatial Reference System of this geometry.",
  "arguments": [{
    "arg": "geometry",
    "description": "a geometry"
  }, {
    "arg": "distance",
    "description": "buffer distance in layer units"
  }, {
    "arg": "segments",
    "optional": true,
    "default": "8",
    "description": "number of segments to use to represent a quarter circle when a round join style is used. A larger number results in a smoother buffer with more nodes."
  }, {
    "arg": "cap",
    "optional": true,
    "default": "'round'",
    "description": "end cap style for buffer. Valid values are 'round', 'flat' or 'square'"
  }, {
    "arg": "join",
    "optional": true,
    "default": "'round'",
    "description": "join style for buffer. Valid values are 'round', 'bevel' or 'miter'."
  }, {
    "arg": "miter_limit",
    "optional": true,
    "default": "2",
    "description": "miter distance limit, for use when the join style is set to 'miter'"
  }],
  "examples": [{
    "expression": "buffer(@geometry, 10.5)",
    "returns": "polygon of the current feature's geometry buffered by 10.5 units"
  }],
  "tags": ["distance", "equal", "spatial", "reference", "calculations", "system", "points", "segments", "miter", "join", "cap", "round"]
}