ST_AsX3D-ApsaraDB RDS(RDS)-阿里云帮助中心

Returns the Extensible 3D (X3D) representation of a geometry object as a text string.

Syntax

text ST_AsX3D(geometry g1, integer maxdecimaldigits, integer options);

Parameter	Type	Description	Default
`g1`	geometry	The geometry object to convert.	Required
`maxdecimaldigits`	integer	The maximum number of decimal places in the output coordinates.	`15`
`options`	integer	Controls coordinate order and GeoCoordinates output. See Options.	`0`

Value	Behavior
`0`	Returns x and y coordinates in database order (default).
`1`	Flips x and y coordinates. When combined with the GeoCoordinates option, applies `latitude_first` by default.
`2`	Returns coordinates in GeoSpatial GeoCoordinates order. The geometry must use WGS 84 (SRID 4326); otherwise the function returns an error. Output: `GeoCoordinate geoSystem='"GD" "WE" "longitude_first"'`.
`3`	Returns the X3D string using `GeoCoordinate geoSystem='"GD" "WE" "latitude_first"'`.

ST_AsX3D supports circular strings, curves, polyhedral surfaces, triangles, triangulated irregular network (TIN) surfaces, and 3D objects.

Convert a 3D polygon to an X3D IndexedFaceSet node:

SELECT ST_AsX3D(ST_GeomFromEWKT('POLYGON((1 1 0,1 2 0,2 2 0,2 1 0,1 1 0))'));

Output:

<IndexedFaceSet  convex='false' coordIndex='0 1 2 3'>
    <Coordinate point='1 1 0 1 2 0 2 2 0 2 1 0 ' />
</IndexedFaceSet>