PostGIS
The pointcloud_postgis
extension adds functions that allow you to use
PostgreSQL Pointcloud with PostGIS, converting PcPoint
and PcPatch
to
Geometry and doing spatial filtering on point cloud data. The
pointcloud_postgis
extension depends on both the postgis
and
pointcloud extensions
, so they must be installed first:
CREATE EXTENSION postgis;
CREATE EXTENSION pointcloud;
CREATE EXTENSION pointcloud_postgis;
PC_Intersects
- PC_Intersects(p pcpatch, g geometry) returns boolean:
- PC_Intersects(g geometry, p pcpatch) returns boolean:
Returns true if the bounds of the patch intersect the geometry.
SELECT PC_Intersects('SRID=4326;POINT(-126.451 45.552)'::geometry, pa)
FROM patches WHERE id = 7;
t
PC_Intersection
- PC_Intersection(pcpatch, geometry) returns pcpatch:
Returns a PcPatch which only contains points that intersected the geometry.
SELECT PC_AsText(PC_Explode(PC_Intersection(
pa,
'SRID=4326;POLYGON((-126.451 45.552, -126.42 47.55, -126.40 45.552, -126.451 45.552))'::geometry
)))
FROM patches WHERE id = 7;
pc_astext
--------------------------------------
{"pcid":1,"pt":[-126.44,45.56,56,5]}
{"pcid":1,"pt":[-126.43,45.57,57,5]}
{"pcid":1,"pt":[-126.42,45.58,58,5]}
{"pcid":1,"pt":[-126.41,45.59,59,5]}
Geometry
- Geometry(pcpoint) returns geometry:
- pcpoint::geometry returns geometry:
Casts PcPoint
to the PostGIS geometry equivalent, placing the x/y/z/m of the
PcPoint
into the x/y/z/m of the PostGIS point.
SELECT ST_AsText(PC_MakePoint(1, ARRAY[-127, 45, 124.0, 4.0])::geometry);
POINT Z (-127 45 124)
PC_EnvelopeGeometry
- PC_EnvelopeGeometry(pcpatch) returns geometry:
Returns the 2D bounds of the patch as a PostGIS Polygon 2D. Useful for performing 2D intersection tests with PostGIS geometries.
SELECT ST_AsText(PC_EnvelopeGeometry(pa)) FROM patches LIMIT 1;
POLYGON((-126.99 45.01,-126.99 45.09,-126.91 45.09,-126.91 45.01,-126.99 45.01))
For example, this is how one may want to create an index:
CREATE INDEX ON patches USING GIST(PC_EnvelopeGeometry(patch));
PC_BoundingDiagonalGeometry
- PC_BoundingDiagonalGeometry(pcpatch) returns geometry:
Returns the bounding diagonal of a patch. This is a LineString (2D), a LineString Z or a LineString M or a LineString ZM, based on the existence of the Z and M dimensions in the patch. This function is useful for creating an index on a patch column.
SELECT ST_AsText(PC_BoundingDiagonalGeometry(pa)) FROM patches;
st_astext
------------------------------------------------
LINESTRING Z (-126.99 45.01 1,-126.91 45.09 9)
LINESTRING Z (-126 46 100,-126 46 100)
LINESTRING Z (-126.2 45.8 80,-126.11 45.89 89)
LINESTRING Z (-126.4 45.6 60,-126.31 45.69 69)
LINESTRING Z (-126.3 45.7 70,-126.21 45.79 79)
LINESTRING Z (-126.8 45.2 20,-126.71 45.29 29)
LINESTRING Z (-126.5 45.5 50,-126.41 45.59 59)
LINESTRING Z (-126.6 45.4 40,-126.51 45.49 49)
LINESTRING Z (-126.9 45.1 10,-126.81 45.19 19)
LINESTRING Z (-126.7 45.3 30,-126.61 45.39 39)
LINESTRING Z (-126.1 45.9 90,-126.01 45.99 99)
For example, this is how one may want to create an index:
CREATE INDEX ON patches USING GIST(PC_BoundingDiagonalGeometry(patch) gist_geometry_ops_nd);