6 Replies Latest reply on Dec 4, 2018 11:39 AM by Kent Marten

    Issue when rendering KML files in Desktop 2018.3

    Krzysztof Obara

      kml-issue.jpg

      Hi, I'm having the issue with rendering KML files in Desktop 2018.3, which work absolutely fine in 2018.2. One is attached to this post. Has anyone had a similar problem? Am I missing anything (I did the same steps in both version)?

      Thanks in advance.

        • 1. Re: Issue when rendering KML files in Desktop 2018.3
          Sarah Battersby

          KML files are sensitive to vertex ordering for polygons.  Starting in Tableau 2018.3, Tableau began rendering polygons according to the semantics of the data source, and KML files have a specific 'vertex ordering' that they follow.  If your vertices are ordered opposite from this, the polygons will be inverted.

           

          From looking at your file, it seems like the vertices are reversed from what is expected and so the polygons are inverted.

           

          What was the original source of the KML file?  It may be that you need to re-generate the KML and reverse the vertices.

           

          If you'd like to take a look at a simple file to explore the difference that the vertex ordering makes, I've attached a simple KML file (two polygons, each with four vertices, one is in a reversed order from the other.  The polygon with 'description' of 1 is reversed from expected, and the polygon with 'description' of 2 has the vertex order as expected.  One will 'invert' in Tableau (example below):

           

          -Sarah

          Tableau Research

          2 of 2 people found this helpful
          • 2. Re: Issue when rendering KML files in Desktop 2018.3
            Sarah Battersby

            A followup point -  I talked with Kent Marten about this and he had a great suggestion -  just save your KML file as a shapefile. Since the shapefile semantics are opposite the KML semantics for vertex ordering, that should fix the problem with bringing the polygons into Tableau.

             

            I went ahead and did that using QGIS and it looks good to me.  Shapefile attached.

             

            -Sarah.

            Tableau Research

            1 of 1 people found this helpful
            • 3. Re: Issue when rendering KML files in Desktop 2018.3
              Kent Marten

              Not to be forgotten, Tableau's built-in geocoding support allows you to assign the "Name" field from the KML file, with the geographic role of State/Province.  Dropping this field on the viz will produce a map of traditional Irish counties.

               

               

              Best,
              Kent M.

              1 of 1 people found this helpful
              • 4. Re: Issue when rendering KML files in Desktop 2018.3
                Krzysztof Obara

                Thanks Kent, but in version 2019.1 Beta 1 the default map inferred from names renders Administrative counties and now my hundred maps are broken (tiny centre of Dublin is surrounded by void - the other administrative counties of Dublin) if I depend on Tableau. Plus the problem was not this map - I've got some proprietary maps prepared for us by an external company - I've just sent this as a freely available public domain example.

                • 5. Re: Issue when rendering KML files in Desktop 2018.3
                  Krzysztof Obara

                  Thank you for the explanationSarah Battersby but changing the default behaviour means potentially invalidating hundreds of dashboards (assuming that each of them needs refreshing with the correct version of the file).

                   

                  Also, according to the email I received from Tableau Support: "The behavior with the maps from a spatial file .kml not being correctly displayed in Tableau Desktop 2018.3 is related to a known issue with ID 845684 confirmed by the Development team. A fix has been included in the upcoming next maintenances releases."

                   

                  This is also confirmed here that it was 'fixed' in version 2018.3.1: Tableau Desktop 2018.3.1 | Tableau Software  (third item from the bottom).

                  And finally, I can confirm that in version 2018.3.1 things are back to normal. Case closed. Thanks to everyone for their input.

                  • 6. Re: Issue when rendering KML files in Desktop 2018.3
                    Kent Marten

                    Hi Kryzsztof,

                     

                    I want to let you know that the geocoding database will be fixed for Ireland in the 2019.1 full release. The picture I posted above is from the working version.

                     

                    Thanks for the feedback.
                    Kent M.

                    1 of 1 people found this helpful