Returns the bounding box of a pcpatch object as a geometry object. Useful for performing 2D intersection tests with Ganos Geometry geometries and building spatial indexes on point cloud data.
Syntax
geometry ST_envelopeGeometry(pcpatch pc);Parameters
| Parameter | Description |
|---|---|
pc | The pcpatch object. |
Description
The returned bounding box is a 2D geometry object of Ganos Geometry.
Examples
Retrieve the bounding box of a patch as well-known text (WKT):
SELECT ST_AsText(ST_EnvelopeGeometry(pa)) FROM patches LIMIT 1;Output:
POLYGON((-126.99 45.01,-126.99 45.09,-126.91 45.09,-126.91 45.01,-126.99 45.01))To speed up spatial queries on point cloud data, create a GIST index on the bounding box:
CREATE INDEX ON patches USING GIST(ST_EnvelopeGeometry(patch));该文章对您有帮助吗？