ST_RaysInGridPolygons

DROP FUNCTION IF EXISTS ST_RaysInGridPolygons(
    geom GEOMETRY)

CREATE OR REPLACE FUNCTION ST_RaysInGridPolygons(
    geom GEOMETRY)
RETURNS TABLE (geom GEOMETRY) AS
$BODY$
    WITH
        tbla AS (SELECT ROW_NUMBER() OVER() as id, (ST_Dump(geom)).geom),
        tblb AS (SELECT id, ST_Boundary(geom) geom FROM tbla),
        tblc AS (SELECT id, ST_MakeLine(pt1, pt2) geom FROM (SELECT id, ST_PointN(geom, generate_series(1, ST_NPoints(geom)-1)) pt1, ST_PointN(geom, generate_series(2, ST_NPoints(geom))) pt2 FROM tblb) AS geom),
        tbld AS (SELECT id, ST_Centroid(geom) geom FROM tblc UNION SELECT id, (ST_DumpPoints(geom)).geom geom FROM tblb),
        tble AS (SELECT id bid, ST_Centroid(geom) geom FROM tbla), 
        tblf AS (SELECT bid, ST_MakeLine(a.geom, b.geom) geom FROM tble a CROSS JOIN (SELECT id, (geom) FROM tbld) b WHERE a.bid=b.id ORDER BY a.bid)
        SELECT geom FROM tblf;
$BODY$
LANGUAGE SQL

SELECT ST_RaysInGridPolygons(geom) geom FROM <grid_polygons>