ST_3DUnion
Name
ST_3DUnion — Perform 3D union
Synopsis
    
     geometry
     
      ST_3DUnion
     
     (
    
    geometry
    
     geom1
    
    , geometry
    
     geom2
    
    
     )
    
    ;
   
Description
Availability: 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).
  
Examples
3D images were generated using PostGIS ST_AsX3D and rendering in HTML using X3Dom HTML Javascript rendering library .
| 
        
 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;
                
       
  
         Original 3D geometries overlaid. geom2 is the one with transparency.  | 
      
        
 SELECT ST_3DUnion(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;
       
  
         Union of geom1 and geom2  |