Basemap is 1.477x to big?

[mirlip]

Hi Domlysz, First of all, your addon is really impressive and useful! I tried to get the basemap align with the 3D DTM from maperitive. But somehow, there is a light scale difference. The 3D model from maperitive aligns perfectly with .osm datas downloaded from the overpass API of openstreetmap. What I've tried so far to solve the problem:

• set blender to metric system
• Set the right CRS system for the location But even with those 2 options, the basemap is bigger. I tried to find the factor by scaling the OSM import and I found it to be around 1.477. Would it be possible to have the basemap have the real scale?

[domlysz]

Hi,

Do you import OSM data with BlenderGEO ?

[mirlip]

I tried both with BlenderGeo and with the official BF plugin (from addon_contrib). The DTM from maperitive is imported with the default collada importer.

[domlysz]

I think is just a CRS issue. BlenderGeo use it's own CRS (transverse mercator centered to scene origin). Basemap CRS depends on the source, for Google, Bing or OSM it's a Web Mercator projection. Web Mercator causes lot of distortion : the further away from the equator, the more the map will be scale up.

For now there is no compatibility between BlenderGIS and BlenderGeo, I'm currently working on a whole refactoring on how BlenderGIS handle georef infos and I hope to be able to fix this compatibility issue.

Maybee a workaround if GDAL is working

• after importing osm data, look the longitude in scene custom properties
• start basemaps and set the CRS to Custom (as Scene) and put this CRS : +a=6378137 +b=6378137 +proj=tmerc +lat_0=0 +lon_0=LONGITUDE +k_0=1 +x_0=0 +y_0=0 +units=m (replace LONGITUDE with the current one set into scene properties)

[mirlip]

Tried it but Blender crashes, will try again after https://github.com/domlysz/BlenderGIS/issues/22 is resolved

[mirlip]

ok, now I can use it. But it then doesn't download the maps and any pan or zoom action brings me very near from 0,0,0 and I can't zoom out anymore.

EDIT: console output is: Can't download tile x0 y0 http://ak.dynamic.t0.tiles.virtualearth.net/comp/ch/?it=A ERROR 1: latitude or longitude exceeded limits The longitude given by BlenderGEO's OSM importer is 7.7516423

[domlysz]

try to run first basemaps with CRS set to "as tile matrix", then zoom a little, level 5 for example and then press spacebar and now switch the CRS to custom

[mirlip]

Yes it works when done through spacebar after "as tile matrix" :)

[domlysz]

10

[mirlip]

In the latest version, after importing a dxf and recalculating the origin, if I start the basemap, it makes the bug mentioned above again: no image displayed, zoom locked. Problem is the sollution above doesn't work anymore. There is no "as tile matrix" anymore. And when I press spacebar, I don't have a custom option anymore. Where those options renamed?

[domlysz]

These old options was just a way to define the scene CRS, now use the new dedicated layout.

• if you your scene crs is the same that the tile matrix crs then the situation is like the old "as tile matrix" option
• if your scene crs is different then it's like the custom option

The problem is that when you start basemap for the first time there isn't any zoom level reference, so it set the zoom level at zero and draw a map of the whole world but not all projection can draw a map of the whole world. When you import a dxf you also set the scene crs and if gdal can't build a world map using this crs then all become broken.

I have already planned to add an option to directly zoom to existing objects when starting basemaps. A workaround when all seems broken, press G then just increase the zoom level and press ok

[mirlip]

After importing this dxf: https://github.com/domlysz/BlenderGIS/files/313506/test1.zip (I modified my dxf importer do.py to have correct lat and long), I started basemap with default parameters: It gives this view, near from cube actually: and then I pressed G and modified the zoom from 0 to 10, but it didn't work either. So I set on 20, it downloaded tiles, zoom was working again, but it was all grey

[domlysz]

The problem come from the source OSM WMS, there was a bug now it's fixed

[domlysz]

just added a new option for automatically center to existing objects https://github.com/domlysz/BlenderGIS/commit/8ad41946e340346722d30fb075a8f74b3ebcab0a

[mirlip]

awesome, it works really good now now and in a very user friendly way :)