This topic describes the ST_AsMVTGeom3D function. This function represents 3D geometries in the title coordinate system.
Syntax
geometry ST_AsMVTGeom3D(
geometry geom,
box2d bounds,
integer extent = 4096,
integer buffer = 256,
boolean clip_geom = true
);Parameters
Parameter | Description |
geom | The 3D geometry object. |
bounds | The rectangular boundaries of the tile, excluding the buffer. |
extent | The size of the tile in the tile coordinate system. Valid values: 256 to 8192. Default value: 4096. |
buffer | The size of the buffer in the tile coordinate system. Valid values: 1 to 4096. Default value: 256. |
clip_geom | Specifies whether the 3D geometry object is clipped by tile boundaries. Default value: true. |
Description
This function is used to represent 3D geometries in the title coordinate system that is required by the ST_AsMVT3D function.
This function is upgraded from the ST_AsMVTGeom function and can be called to transform the z-axis data of a 3D geometry.
This function requires tile rectangle boundaries in the required spatial coordinate so that the geometry can be transformed and clipped when necessary. You can call the ST_TileEnvelope function to generate boundaries.
This function cannot be called to transform 3D polygon objects that have inner shells in a 3D geometry object.
Examples
SELECT ST_AsText(ST_AsMVTGeom3D(ST_Transform('SRID=4326; LINESTRING(-10 -10 30, -10 -20 30)'::geometry, 3857), ST_TileEnvelope(1, 0, 0))) AS geom;
geom
------------------------------------------------------------------------------------
MULTILINESTRING Z ((3868.44444444444 4324.7197219642 30,3868.44444444444 4352 30))
(1 row)