[postgis-tickets] [PostGIS] #3705: ST_AsX3D needs improvement

[PostGIS]

#3705: ST_AsX3D needs improvement
------------------------+---------------------------
 Reporter:  Mike Toews  |      Owner:  pramsey
     Type:  defect      |     Status:  new
 Priority:  medium      |  Milestone:  PostGIS 2.3.3
Component:  postgis     |    Version:  2.3.x
 Keywords:              |
------------------------+---------------------------
 Testing ST_AsX3D on various geometries gives varied and interesting
 results with PostGIS 2.3 on Windows. These are non-critical outputs,
 separated from critical outputs in #3704

 Some are documented not to be implemented, however they still run without
 raising a "'X' geometry type not implemented" error. The documentation
 should also mention that M-coordinates (where present) are dropped.

  `SELECT ST_AsX3D('POLYGON EMPTY');`:: returns invalid XML:
 `<IndexedFaceSet  convex='false' coordIndex=''>' />`

  `SELECT ST_AsX3D('POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))');`::
 returns invalid XML: `<IndexedFaceSet  convex='false' coordIndex='0 1 2
 3'>30 10 40 40 20 40 10 20 ' />`, and similar for empty and non-empty
 MULTIPOLYGON


  `SELECT ST_AsX3D('MULTILINESTRING ((2 3, 4 5))');`:: returns invalid XML:
 `<IndexedLineSet  coordIndex='0 1'>2 3 4 5 ' />`

 With the following, valid XML is returned (I can't confirm if these are
 valid X3D):

  * `POINT(1 2)` : `1 2`
  * `LINESTRING(1 2, 3 4)` : `<LineSet  vertexCount='2'><Coordinate
 point='1 2 3 4' /></LineSet>`
  * `MULTIPOINT EMPTY` : `<Polypoint2D  point='' />`
  * `TRIANGLE((0 0 0,0 1 0,1 1 0,0 0 0))` : `0 0 0 0 1 0 1 1 0`
  * `TIN (((0 0 0, 0 0 1, 0 1 0, 0 0 0)), ((0 0 0, 0 1 0, 1 1 0, 0 0 0)))`
 : `<IndexedTriangleSet  index='0 1 2 3 4 5'><Coordinate point='0 0 0 0 0 1
 0 1 0 0 0 0 0 1 0 1 1 0'/></IndexedTriangleSet>`
  * `POLYHEDRALSURFACE Z (((0 0 0, 0 1 0, 1 1 0, 1 0 0, 0 0 0)),((0 0 0, 0
 1 0, 0 1 1, 0 0 1, 0 0 0)),((0 0 0, 1 0 0, 1 0 1, 0 0 1, 0 0 0)),((1 1 1,
 1 0 1, 0 0 1, 0 1 1, 1 1 1)),((1 1 1, 1 0 1, 1 0 0, 1 1 0, 1 1 1)),((1 1
 1, 1 1 0, 0 1 0, 0 1 1, 1 1 1)))` : ` <IndexedFaceSet convex='false'
 coordIndex='0 1 2 3 -1 4 5 6 7 -1 8 9 10 11 -1 12 13 14 15 -1 16 17 18 19
 -1 20 21 22 23'><Coordinate point='0 0 0 0 1 0 1 1 0 1 0 0 0 0 0 0 1 0 0 1
 1 0 0 1 0 0 0 1 0 0 1 0 1 0 0 1 1 1 1 1 0 1 0 0 1 0 1 1 1 1 1 1 0 1 1 0 0
 1 1 0 1 1 1 1 1 0 0 1 0 0 1 1' /></IndexedFaceSet>`

 However some of these don't work within a `GEOMETRYCOLLECTION` (the
 documentation does not indicate the support level of this geometry type):
  `SELECT ST_AsX3D('GEOMETRYCOLLECTION(POINT(1 2),LINESTRING(1 2, 3
 4))');`:: returns invalid XML: `<Shape>1 2<Shape><LineSet
 vertexCount='2'><Coordinate point='1 2 3 4' /></LineSet>`
 or
  `SELECT ST_AsX3D('GEOMETRYCOLLECTION(POINT(1 2),POINT(3 4))');`:: returns
 invalid XML: `<Shape>1 2<Shape>3 4`

--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/3705>
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