Among others, i am deploying my own custom WMS.
Based on OpenStreetMap and Geoserver,i got it working i.e. to get Tableau Desktop retrieve tiles from my customer WMS.
But i run into a couple of 'inconveniences' and looking forward to see your comment on those issues.
I've read a lot of postings on WMS here and it was stated that Tableau would request tile in EPSG:4326 projection.
Question 1: Is this actually true?
Looking at the URL Tableau fires towards my WMS, reported in Tableau's log-file (i wrapped the text around):
2012-04-25 15:04:23.136 (0444): Solid color tile returned from 'http://192.168.56.82:8080/geoserver/wms?SERVICE=WMS&bbox=7.4225,43.6993,7.4530,43.7299&format=image/png&height=712&
It's clear Tableau requests EPSG:4269 and not EPSG:4326 although provided by my WMS.
Looking at the result in Tableau, i am not satisfied. Have a look at the attached screenshots.
P1 showing the default online tableau map @ zoomlevel 16 in 4 tiles of 747x821pixels. Looking fine but my customer wants to see buildings which are not in the Tableau Map
P2 showing the same area thru my custom WMS. Tableau logfile report @ zoomlevel 13 with 4 tiles 705x821. The picture is already a bit fading.
P3 showing a must larger area which Tableau also requests my WMS @ zoomlevel 13 using 9 tiles 705x821. Nothing wrong with that. Nice usable, showable picture.
P4 Showing this map zoomed in at maximum in Tableau. Map is still shown @ zoomlevel 13 using a single tile. The result is not presentable to my customer. Tableau is still at zoomlevel 13 on my WMS but even on a larger area in Tableau map on zoomlevel 16 (P1)
P5 Shows my WMS via OpenLayers website on the P4 area which is a usable, presentable pic. I.e my WMS can produce nice pics. (Pls notice zoomlevel 18 on OpenLayers is not comparable with the zoomlevel scale in Tableau).
Question 2: How can you direct/infleunce the Tableau zoomlevel?
I can imation that Tableau wants to reduce tile-requests on 'their' Urban Mapping server. (Today displaying red-crossed-tiles repeatingly).
But when you are in control of infrastructure and your own WMS, how can you achieve using its full capabilities?
Question 3: What WMS-URL variables could be used in conjuction with Tableau?
Feel free to join this discussion?