[MapProxy] MBTiles shift, EPSG:3857 proj

[Fernando Ribeiro]

Hi list,

I have been struggling the last hours, trying to find out the origin of a
small shift (around 10m NE) I detected in tiles origin on a MBTiles files
generated with Tilemill. In the attached picture I overlay the shapefiles
(in wgs84) used on the mbtiles file generation.

My MapProxy grid config looks like this:

....
grids:
  GRID_SA_256_Google:
    srs: 'EPSG:3857'
    bbox:
[-20037508.342789236,-20037508.342789236,20037508.342789236,20037508.342789236]
    tile_size: [256, 256]
    res:
[156543.033928,78271.516964,39135.758482,19567.879241,9783.939621,4891.969810,2445.984905,1222.992453,611.496226,305.748113,152.874057,76.437028,38.218514,19.109257,9.554629,4.777314,2.388657,1.194329,0.597164,0.298582,0.149291]


Is this grid valid? I googled around for the default values for Google/OSM
grid specifications.

Thanks,
-- 
Fernando Ribeiro
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