This is a follow up to a thread I started last week where I thought QGIS server may have been shifting WMS layers on our Arches instance.
After further investigation it appears the artifact may be an Open Layers issues. When adding WMS layers as overlays and having a "gutter" attribute to buffer the tiles, the layers appeared shifted from their proper geographic locations. This only appeared on certain computers (2 out of 5 that we tested) and on 4 mobile devices (2 iOS, 2 Android), on the other computers there was no shift at all. I narrowed this issue down to the "gutter" attribute. When this was set to 0 everything lined up as expected. I served up the same layer on both QGIS server and Geoserver and saw consistent results. I also tested this on JS Bin which removed Arches from the equation completely. I have attached framegrabs from JS Bin below. It appears this was a known issue in OL2 but was eventually fixed : http://lists.osgeo.org/pipermail/openlayers-dev/2012-April/008644.html This obviously isn't a huge issue for a lot of people, and it is really strange that it only affects certain devices, but thought I would post it here as it may be important to some people. Our workaround will likely be to only use the gutter attribute on the layers that absolutely need it (points, labels) and try to make that gutter as small as possible (it appears to be linear). Glad that it isn't a QGIS Server issue as we have found that to be very easy to use. I am open to any suggestions if other have them. Most likely I will try and post something on the Open Layers forum. Andy <https://lh3.googleusercontent.com/-WzmuIZ6BiGs/VqaC4Ae74bI/AAAAAAAAFgc/W6OYSFuqBAc/s1600/OL3-gutterissue.jpg> -- -- To post, send email to [email protected]. To unsubscribe, send email to [email protected]. For more information, visit https://groups.google.com/d/forum/archesproject?hl=en --- You received this message because you are subscribed to the Google Groups "Arches Project" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
