Opened 10 years ago
Closed 10 years ago
#3149 closed defect (invalid)
3D-Distance/KNN distances don't agree sometimes
Reported by: | robe | Owned by: | pramsey |
---|---|---|---|
Priority: | blocker | Milestone: | PostGIS 2.2.0 |
Component: | postgis | Version: | master |
Keywords: | Cc: |
Description
I started putting together the knn recheck tests for 3d, all was good until I got into more complex types:
— script to create the 3d geometry table is as follows:
CREATE TABLE knn_recheck_geom_nd(gid serial primary key, geom geometry); INSERT INTO knn_recheck_geom_nd(gid,geom) SELECT ROW_NUMBER() OVER(ORDER BY x,y) AS gid, ST_MakePoint(x*0.777,y*0.887,z*1.05) As geom FROM generate_series(-100,1000, 7) AS x , generate_series(-300,1000,9) As y, generate_series(1005,10000,5555) As z ; -- 3d lines INSERT INTO knn_recheck_geom_nd(gid, geom) SELECT 500000 + i, ST_Translate('LINESTRING(-100 300 500, 500 700 600, 400 123 0, 500 10000 -1234, 1 1 5000)'::geometry, i*2000,0) FROM generate_series(0,10) i; -- 3d polygons INSERT INTO knn_recheck_geom_nd(gid, geom) SELECT 500100 + i, ST_Translate('POLYGON((100 800 5678, 100 700 5678, 400 123 5678, 405 124 5678, 100 800 5678))'::geometry,0,i*2000) FROM generate_series(0,3) i; -- polyhedral surface -- INSERT INTO knn_recheck_geom_nd(gid,geom) SELECT 600000 + row_number() over(), ST_Translate(the_geom,100, 450,1000) As the_geom FROM (VALUES ( ST_GeomFromText( 'PolyhedralSurface( ((0 0 0, 0 0 1, 0 1 1, 0 1 0, 0 0 0)), ((0 0 0, 0 1 0, 1 1 0, 1 0 0, 0 0 0)), ((0 0 0, 1 0 0, 1 0 1, 0 0 1, 0 0 0)), ((1 1 0, 1 1 1, 1 0 1, 1 0 0, 1 1 0)), ((0 1 0, 0 1 1, 1 1 1, 1 1 0, 0 1 0)), ((0 0 1, 1 0 1, 1 1 1, 0 1 1, 0 0 1)) )') ) , ( ST_GeomFromText( 'PolyhedralSurface( ((0 0 0, 0 0 1, 0 1 1, 0 1 0, 0 0 0)), ((0 0 0, 0 1 0, 1 1 0, 1 0 0, 0 0 0)) )') ) ) As foo(the_geom) ;
The results of this test don't agree with the ST_3DDistance answer:
SELECT '#2nd-3' As t, gid, ST_GeometryType(geom), ST_3dDistance( 'MULTILINESTRING((-95 -300 5000, 100 450 1000, 100 323 200),(-50 2000 456, 30 6000 789))'::geometry, geom)::numeric(12,4), 'MULTILINESTRING((-95 -300 5000, 100 450 1000, 100 323 200),(-50 2000 456, 30 6000 789))'::geometry <<->> geom As knn_dist FROM knn_recheck_geom_nd ORDER BY 'MULTILINESTRING((-95 -300 5000, 100 450 1000, 100 323 200),(-50 2000 456, 30 6000 789))'::geometry <<->> geom LIMIT 5;
t | gid | st_geometrytype | st_3ddistance | knn_dist --------+--------+-----------------+---------------+------------------ #2nd-3 | 500000 | ST_LineString | 47.9294 | 2275.46599623022 #2nd-3 | 4640 | ST_Point | 447.4051 | 2500.71300499541 #2nd-3 | 4349 | ST_Point | 448.6050 | 2500.715907504 #2nd-3 | 4929 | ST_Point | 446.2682 | 2500.72193218324 #2nd-3 | 4060 | ST_Point | 449.8674 | 2500.73063966772 (5 rows)
I think the knn_dist answer is wrong because I purposely carefully constructed my multilinestring so it would cut into my polyhedral surface, and my polyhedral surface is no where in sight in this query:
SELECT ST_3dDistance( 'MULTILINESTRING((-95 -300 5000, 100 450 1000, 100 323 200),(-50 2000 456, 30 6000 789))'::geometry, geom)::numeric(12,4), 'MULTILINESTRING((-95 -300 5000, 100 450 1000, 100 323 200),(-50 2000 456, 30 6000 789))'::geometry <<->> geom As knn_dist from knn_recheck_geom_nd where gid = 600001; st_3ddistance | knn_dist ---------------+------------------ 0.0000 | 2885.41236221099
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oops hold on just realized my install is old for some reason. Let me build with latest and then complain