[PostGIS] #5817: CG_3DIntersection gives wrong result with LINESTRING and Solid

[PostGIS]

#5817: CG_3DIntersection gives wrong result with LINESTRING and Solid
----------------------+---------------------------
 Reporter:  nbvfgh    |      Owner:  lbartoletti
     Type:  defect    |     Status:  new
 Priority:  critical  |  Milestone:  PostGIS 3.5.1
Component:  sfcgal    |    Version:  3.5.x
 Keywords:            |
----------------------+---------------------------
 {{{
 SELECT ST_IsClosed('POLYHEDRALSURFACE Z (
 ((-1 1 -1,1 1 -1,1 -1 -1,-1 -1 -1,-1 1 -1)),
 ((-1 1 1,-1 -1 1,1 -1 1,1 1 1,-1 1 1)),
 ((-1 1 -1,-1 1 1,1 1 1,1 1 -1,-1 1 -1)),
 ((1 1 -1,1 1 1,1 -1 1,1 -1 -1,1 1 -1)),
 ((1 -1 -1,1 -1 1,-1 -1 1,-1 -1 -1,1 -1 -1)),
 ((-1 -1 -1,-1 -1 1,-1 1 1,-1 1 -1,-1 -1 -1)))');

 -- result:{true}
 }}}
 Then we make the closed POLYHEDRALSURFACE a Solid, and use
 CG_3DIntersection to get the Interaction with the Solid and Linestring,
 which we get the unexpected result.
 {{{
 WITH solid AS (
     SELECT
         CG_MakeSolid('POLYHEDRALSURFACE Z (
                 ((-1 1 -1,1 1 -1,1 -1 -1,-1 -1 -1,-1 1 -1)),
                 ((-1 1 1,-1 -1 1,1 -1 1,1 1 1,-1 1 1)),
                 ((-1 1 -1,-1 1 1,1 1 1,1 1 -1,-1 1 -1)),
                 ((1 1 -1,1 1 1,1 -1 1,1 -1 -1,1 1 -1)),
                 ((1 -1 -1,1 -1 1,-1 -1 1,-1 -1 -1,1 -1 -1)),
                 ((-1 -1 -1,-1 -1 1,-1 1 1,-1 1 -1,-1 -1 -1)))')
      geom
 )
 SELECT
         ST_AsText(CG_3DIntersection(
         'LINESTRING (-2 0 0, 2 0 2)'::geometry,
         solid.geom
         )),
         ST_AsText(CG_3DIntersection(
         'LINESTRING (-2 0 0,0 0 1,2 0 2)'::geometry,
         solid.geom
         ))
 FROM solid;

 -- expected: {{LINESTRING Z (-1 0 0.5,0 0 1)},{LINESTRING Z (-1 0 0.5,0 0
 1)}}
 -- actual  : {{POINT Z (-1 0 0.5)},{LINESTRING Z (-1 0 0.5,0 0 1)}}
 }}}

 To verify that the issue is not caused by differences in the two
 Linestrings, we ran the following query:

 {{{
 SELECT
     ST_AsText(CG_3DIntersection(
         'LINESTRING (-2 0 0,2 0 2)'::geometry,
         'POLYHEDRALSURFACE Z (((-1 1 -1,1 1 -1,1 -1 -1,-1 -1 -1,-1 1
 -1)),((-1 1 1,-1 -1 1,1 -1 1,1 1 1,-1 1 1)),((-1 1 -1,-1 1 1,1 1 1,1 1
 -1,-1 1 -1)),((1 1 -1,1 1 1,1 -1 1,1 -1 -1,1 1 -1)),((1 -1 -1,1 -1 1,-1 -1
 1,-1 -1 -1,1 -1 -1)),((-1 -1 -1,-1 -1 1,-1 1 1,-1 1 -1,-1 -1 -1)))'
     )),
     ST_AsText(CG_3DIntersection(
         'LINESTRING (-2 0 0,0 0 1,2 0 2)'::geometry,
         'POLYHEDRALSURFACE Z (((-1 1 -1,1 1 -1,1 -1 -1,-1 -1 -1,-1 1
 -1)),((-1 1 1,-1 -1 1,1 -1 1,1 1 1,-1 1 1)),((-1 1 -1,-1 1 1,1 1 1,1 1
 -1,-1 1 -1)),((1 1 -1,1 1 1,1 -1 1,1 -1 -1,1 1 -1)),((1 -1 -1,1 -1 1,-1 -1
 1,-1 -1 -1,1 -1 -1)),((-1 -1 -1,-1 -1 1,-1 1 1,-1 1 -1,-1 -1 -1)))'
     ));
 -- expected: {{MULTIPOINT Z ((-1 0 0.5),(0 0 1))},{MULTIPOINT Z ((-1 0
 0.5),(0 0 1))}
 -- actual  : {{MULTIPOINT Z ((-1 0 0.5),(0 0 1))},{MULTIPOINT Z ((-1 0
 0.5),(0 0 1))}
 }}}
 The intersection between the original POLYHEDRALSURFACE and these two
 linestrings yielded the same result, so there should be some bugs in the
 operation of the intersection between Solid and Linestring.
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/5817>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.