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Computes the straight skeleton of a polygonal geometry. The straight skeleton is a method of representing a polygon by a topological skeleton, formed by a continuous shrinking process where each edge moves inward in parallel at a uniform speed. This function uses the weighted straight skeleton algorithm based on Felkel’s approach. This function may have significant performance limitations when processing polygons with a very large number of vertices. For very large polygons (e.g., 10,000+ vertices), applying vertex reduction or simplification is essential to achieve practical computation times.

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Signatures

ST_StraightSkeleton(geom: Geometry)

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Parameters

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geom
Geometry
required
The input geometry.

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Return type

The resulting geometry.

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Examples

SELECT ST_StraightSkeleton(
  ST_GeomFromWKT('POLYGON ((45 0, 55 0, 55 40, 70 40, 70 50, 30 50, 30 40, 45 40, 45 0))')
)

MULTILINESTRING ((50 5, 50 45), (50 45, 35 45), (50 45, 65 45), (35 45, 30 45), (35 45, 40 40), (65 45, 70 45), (65 45, 60 40), (50 5, 45 5), (50 5, 55 5))
ST_StraightSkeleton

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Simple Square

SELECT ST_StraightSkeleton(
  ST_GeomFromWKT('POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))')
)

MULTILINESTRING ((5 5, 0 5), (5 5, 5 0), (5 5, 10 5), (5 5, 5 10))