Name
ST_3DDifference — 执行三维差异
Synopsis
geometry ST_3DDifference(geometry geom1, geometry geom2);
描述
返回geom1中不属于geom2的部分。
可用性：2.2.0
This method needs SFCGAL backend.
This function supports 3d and will not drop the z-index.
This function supports Polyhedral surfaces.
This function supports Triangles and Triangulated Irregular Network Surfaces (TIN).
示例
3D图像是使用PostGIS生成的 ST_AsX3D 并使用以下命令在HTML中呈现 X3Dom HTML Java脚本渲染库 。
SELECT ST_Extrude(ST_Buffer(ST_GeomFromText('POINT(100 90)'),
50, 'quad_segs=2'),0,0,30) AS geom1,
ST_Extrude(ST_Buffer(ST_GeomFromText('POINT(80 80)'),
50, 'quad_segs=1'),0,0,30) AS geom2;
 覆盖原始3D几何图形。Geom2是将被移除的部分。 |
SELECT ST_3DDifference(geom1,geom2)
FROM ( SELECT ST_Extrude(ST_Buffer(ST_GeomFromText('POINT(100 90)'),
50, 'quad_segs=2'),0,0,30) AS geom1,
ST_Extrude(ST_Buffer(ST_GeomFromText('POINT(80 80)'),
50, 'quad_segs=1'),0,0,30) AS geom2 ) As t;
 移除geom2后还剩下什么 |