Esri shapefile conversion

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helwin
Posts: 65
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Re: Esri shapefile conversion

Post by helwin » Mon Apr 26, 2021 5:48 pm

I watched all tutorials, so now I am a QGIS master :D , converted contours to mbtiles like you suggested.

Fact is, zoom scales in QGIS do not match in Alpinequest.

E.g. when I specify Zoom 16 to 17 in QGIS, in Alpinequest it´s (1) to 15.

QGIS 16 to 18 turns out until 17 in Alpinequest, 16 to 19 until 19.

Screenshot taken at Zoom level 9, mind that in QGIS I specified 16-19:
from Level 10 to end:
Any ideas?

Psyberia-Support
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Re: Esri shapefile conversion

Post by Psyberia-Support » Mon Apr 26, 2021 7:06 pm

What is displayed in AlpineQuest is the level of details number of the main map, starting from 1. If you have a map with 3 distincts levels of details, they will be numbered as 1/3, then 2/3 and 3/3.
Now if you want to also display the equivalent OSM zoom ID (which the MBTile format also follows), you can use this user setting:

Code: Select all

map.canvas.display_osm_zoom_id=true
But all formats have their own scales, not necessarily bound to how OSM compute their zoom levels.
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helwin
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Joined: Sun Jun 16, 2019 2:32 pm

Re: Esri shapefile conversion

Post by helwin » Mon Apr 26, 2021 7:26 pm

Thanx for the Info.

The level offset is not that big of a problem once you know about it, what is annoying is the fact that these .mbtiles are displayed on levels not sspecified in QGIS, so they look like a solid block (first screenshot).

Do you think that this is a bug in QGIS or a problem in Alpinequest?

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Re: Esri shapefile conversion

Post by Psyberia-Support » Mon Apr 26, 2021 7:34 pm

I don't think there is any problem, it's just that you're not comparing the same levels, the numbers does not refer to the same things.
The only thing you can compare is the scale value, ie "1:219,000" and so on.

And when you see the map displayed as a blue area (first screenshot), it means that you have a map displayed that covers this area but the zoom scale is too different to be displayable at the current scale, so you need to zoom in.
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helwin
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Re: Esri shapefile conversion

Post by helwin » Mon Apr 26, 2021 7:55 pm

Psyberia-Support wrote:
Mon Apr 26, 2021 7:34 pm
And when you see the map displayed as a blue area (first screenshot), it means that you have a map displayed that covers this area but the zoom scale is too different to be displayable at the current scale, so you need to zoom in.
Ok so this is the intended behavior
Psyberia-Support wrote:
Mon Apr 26, 2021 7:34 pm
I don't think there is any problem, it's just that you're not comparing the same levels, the numbers does not refer to the same things.
The only thing you can compare is the scale value, ie "1:219,000" and so on.
So do you know of a workaround? Because QGIS only lets me choose by zoom level, not by scale value when converting to mbtiles....All I want is these contours to kick in around , let´s say 1: 15 000 and less, and above nothing should be visible at all, also no blue area of course....

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Re: Esri shapefile conversion

Post by Psyberia-Support » Tue Apr 27, 2021 9:52 am

Add the user setting I gave you above, and AQ will also display the zoom level number used by QGIS.
Otherwise you can use this table to get the scale of each zoom level number: https://wiki.openstreetmap.org/wiki/Zoom_levels
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helwin
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Re: Esri shapefile conversion

Post by helwin » Tue Apr 27, 2021 6:57 pm

Still the same as before with this setting. I will try more options and report again. Thank you for your great support so far!

hamish
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Re: Esri shapefile conversion

Post by hamish » Tue Apr 27, 2021 8:30 pm

Would it be possible to have a user setting to turn off the blue overlay - so if a map layer isn't displayable at a particular zoom level you can carry on using the layers that will display uninterrupted.

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Re: Esri shapefile conversion

Post by Psyberia-Support » Wed Apr 28, 2021 7:54 am

Concerning the user setting to display the QGIS zoom levels, please double check you've correctly written it and restarted the app.
It should appear like this:
Image

Concerning the blue area, I can add an user setting to disable it in the next update.
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helwin
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Re: Esri shapefile conversion

Post by helwin » Wed Apr 28, 2021 8:21 am

Yes, it looks like this. Map starts at 1/15 (3) and goes up to15/15 (23). Blue area until 9/15(13), contours displayed from 10/15(14) to 15/15(23).

Mbtiles conversion was specified from zoom level 16 to 19 in QGIS.

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Re: Esri shapefile conversion

Post by Psyberia-Support » Wed Apr 28, 2021 8:29 am

Yes it seems coherent.
Your contours layers zoom levels go from 16 to 19, but the application will underscale the first level and overscale the last one a little bit, so it's effectively displayed from 14 to 23.
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helwin
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Re: Esri shapefile conversion

Post by helwin » Wed Apr 28, 2021 9:14 am

Ah....ok!

Works fine now with setting zoom levels just from 17 to 18. Waiting for the update to lose that blue area! Thanks a lot!

helwin
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Re: Esri shapefile conversion

Post by helwin » Sat May 01, 2021 5:09 pm

Psyberia-Support wrote:
Wed Apr 28, 2021 8:29 am
Your contours layers zoom levels go from 16 to 19, but the application will underscale the first level and overscale the last one a little bit, so it's effectively displayed from 14 to 23.
Is it possible to add a user setting to avoid this over/underscaling? I want to display also the 5 meter contours, I am planning to display these only at the last zoom level but it´s not usable with this kind of overlap.

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Re: Esri shapefile conversion

Post by Psyberia-Support » Sat May 01, 2021 6:43 pm

You can use those user settings to set how many levels to under or over scale. Those settings only apply to file based maps.
By default it's:

Code: Select all

maps.features.offlinemaps.underscaling_levels=2
maps.features.offlinemaps.overscaling_levels=4
This should disable under and over scaling:

Code: Select all

maps.features.offlinemaps.underscaling_levels=0
maps.features.offlinemaps.overscaling_levels=0
For calibrated images, those values are multiplied by 3.
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helwin
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Joined: Sun Jun 16, 2019 2:32 pm

Re: Esri shapefile conversion

Post by helwin » Sat May 01, 2021 7:21 pm

There seems to be a problem, this seems to override the "map.canvas.display_osm_zoom_id=true" setting. Can you check?

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