Zoom 4 relief x-y positioning is off, and extremely off by the ±180 anti-meridian

tilezen / joerd

Joerd can be used to download, merge and generate tiles from digital elevation data

MIT License

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Zoom 4 relief x-y positioning is off, and extremely off by the ±180 anti-meridian #164

Open nvkelso opened 6 years ago

nvkelso commented 6 years ago

Seems to be worse above a certain latitude, too?

http://tangrams.github.io/walkabout-style/#4/60.61/-134.60

v1.0

v1.1

mojodna commented 6 years ago

I'm pretty sure that this is related to https://trac.osgeo.org/gdal/ticket/7020 where the offsets get magnified on each overview level.

nvkelso commented 6 years ago

By magnified you mean each zoom out from the "1 pixel" offset gets a few more offsets?

One option is for us to not overwrite the v1.0 bucket's low zoom tile content at all. Doesn't solve the problem, but may be a shippable solution now while the upstream bug is sorting itself out.

mojodna commented 6 years ago

Yup, that's my gut thinking.

If the current low zoom tiles are good enough, that makes sense to me.

iandees commented 6 years ago

(I moved several comments I mistakenly added to this ticket over to https://github.com/tilezen/joerd/issues/165)

nvkelso commented 6 years ago

This bothers me less and less on subsequent views – but is still a problem we should fix.