Name
CG_Buffer3D — Computes a 3D buffer around a geometry.
Synopsis
geometry CG_Buffer3D(geometry geom, float8 radius, integer segments, integer buffer_type);
描述
Generates a 3D buffer around the input geometry geom with a specified radius. The buffer is constructed in 3D space, creating a volumetric representation of the geometry's surroundings. The segments parameter defines the number of segments used to approximate the curved sections of the buffer. The buffer_type specifies the type of buffer to create: 0: Rounded buffer (default) 1: Flat buffer 2: Square buffer
Availability: 3.6.0 - requires SFCGAL >= 2.0.0
该方法需要SFCGAL后端。
该函数支持 3d 并且不会丢失 z-index。
该函数支持多面体曲面。
此函数支持三角形和不规则三角网面 (TIN)。
示例
SELECT ST_AsText(CG_Buffer3D('POINT(0 0 0)', 1, 8, 0));
-- Result: POLYHEDRALSURFACE Z (((0 0 1, 0.5 -0.5 0.71, 0 -0.71 0.71, 0 0 1)), ... )
The following images were rendered pasting the output of the ST_AsX3D query into X3D Viewer.
SELECT string_agg('<Shape
>' || ST_AsX3D(cgbuffer3d_output) || '<Appearance>
<Material diffuseColor="0 0.8 0.2" specularColor="0 1 0"/>
</Appearance>
</Shape
>', '');
segments=32 (rounded buffer)
SELECT CG_Buffer3D(ST_GeomFromText('POINT(100 90)'), 50,32,0);
|
5 segments rounded
SELECT CG_Buffer3D(
ST_GeomFromText('POINT(100 90)'),
50,5,0);
|
32 segments, round
SELECT CG_Buffer3D(
ST_GeomFromText(
'LINESTRING(50 50,150 150,150 50)'
),
10,32,0);
|
32 segments, square
SELECT CG_Buffer3D(
ST_GeomFromText(
'LINESTRING(50 50,150 150,150 50)'
),
10,32,2);
|