CG_StraightSkeleton — Compute a straight skeleton from a geometry
geometry CG_StraightSkeleton(geometry geom, boolean  use_distance_as_m = false);
Availability: 3.5.0
Requires SFCGAL >= 1.3.8 for option use_distance_as_m
            
            This method needs SFCGAL backend.
        
            
            This function supports 3d and will not drop the z-index.
        
            
            This function supports Polyhedral surfaces.
        
            
            This function supports Triangles and Triangulated Irregular Network Surfaces (TIN).
        
SELECT CG_StraightSkeleton(ST_GeomFromText('POLYGON (( 190 190, 10 190, 10 10, 190 10, 190 20, 160 30, 60 30, 60 130, 190 140, 190 190 ))'));
        ST_AsText(CG_StraightSkeleton('POLYGON((0 0,1 0,1 1,0 1,0 0))', true);
        MULTILINESTRING M ((0 0 0,0.5 0.5 0.5),(1 0 0,0.5 0.5 0.5),(1 1 0,0.5 0.5 0.5),(0 1 0,0.5 0.5 0.5))
![]() Original polygon  | 
                ![]() Straight Skeleton of polygon  |