Hi Erik,
I think maybe there's a nomenclature problem here. I wasn't aware that
any Google services were available via WMS.
WMS is a specific specification, and if you're googling around using
that term you're going to find results that aren't pertinent to what you
actually want to do (which is using Google's tile based, non-WMS services).
Cheers,
Jonathan
On 2019-04-09 08:54, Erik Polzin wrote:
I'm busy developing an app using the QGIS Python api, PyQGIS, and am
noticing some strange behaviour when loading WMS tiles: Running the python
script on Linux Mint loads xyz layers from Google Maps and Google Satellite
just fine. On Windows, only the Google Maps layer loads.
Here is a test script I wrote to demonstrate the problem:
from qgis.core import QgsApplication, QgsProject, QgsRasterLayer
from qgis.gui import QgsMapCanvas, QgsLayerTreeMapCanvasBridge
from PyQt5.QtWidgets import QMainWindow
import os
GOOGLE_MAPS_SOURCE = "type=xyz&url=
https://mt1.google.com/vt?lyrs%3Dm%26x%3D%7Bx%7D%26y%3D%7By%7D%26z%3D%7Bz%7D&zmax=19&zmin=0
"
GOOGLE_SATELLITE_SOURCE = "type=xyz&url=
https://mt1.google.com/vt?lyrs%3Ds%26x%3D%7Bx%7D%26y%3D%7By%7D%26z%3D%7Bz%7D&zmax=19&zmin=0
"
class WMSTestApp(QMainWindow):
def __init__(self):
super().__init__()
self.canvas = QgsMapCanvas(self)
self.bridge =
QgsLayerTreeMapCanvasBridge(QgsProject.instance().layerTreeRoot(),
self.canvas)
layer = QgsRasterLayer(GOOGLE_SATELLITE_SOURCE, "Test WMS Layer",
"wms")
QgsProject.instance().addMapLayer(layer)
self.canvas.setLayers([layer])
self.setCentralWidget(self.canvas)
QgsApplication.setPrefixPath(os.environ.get("QGIS_PREFIX_PATH", "C:\Program
Files\QGIS 3.4\apps\qgis"), True)
qgs = QgsApplication([], True)
qgs.initQgis()
app = WMSTestApp()
app.show()
qgs.exec_()
qgs.exitQgis()
Interestingly, the layers (from the same sources!) both load from the
Windows QGIS app.
So I did some digging and noticed that the default Google Maps url returns
PNG files, while the Satellite url returns JPEGs. I tested a couple of
other links, and it seems like only PNG tile servers have any effect on
windows systems.
Have tested this on Windows 7 and 10, with the same results.
Does PyQgis need to be reconfigured in some way to get this to work? Or is
it a known issue with the version (3.4) I'm using?
Cheers and thanks,
Erik
_______________________________________________
QGIS-Developer mailing list
[email protected]
List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
_______________________________________________
QGIS-Developer mailing list
[email protected]
List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
