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jvangeld / ME-GIS

GIS files created by the ME-DEM team.
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Spatial reference system? #15

Open Skoda091 opened 4 years ago

Skoda091 commented 4 years ago

Hi, Truly great work on those GIS data! I would like to use them for learning purposes, concerning GIS data and leaflet.js. My goal is to just create an interactive Middle-Earth map. Obviously for non-commercial usage.

I have a technical question. Just to remind you, I have no experience with spatial data. I've loaded the whole project to QGIS, and it showed that EPSG:32631 is used for those data as an SPS/CRS. So, I used Proj4Leaflet to use a custom coordinate system. I've been able to render some GIS data (e.g Cities) using Leaflet in browser, but the problem is that they are placed in a completely wrong position. The same with Coastlines. So my conclusion is that I did something wrong with the coordinate system. Maybe I use incorrect SRS? Which one should be used with those GIS data?

hellricer commented 4 years ago

The EPSG:32631 or WGS 84 / UTM zone 31N is in fact the projection in use.

I'm not sure what you mean by "completely wrong position", though. Relative to each other?

But in any case, there are definitely problems with our CRS which we acknowledge in issue #13. I would say that this issue is the duplicate of it.

We're currently trying to get more knowledgeable people on-board to help us sort this out.

Skoda091 commented 4 years ago

Relative to each other?

Exactly!

But in any case, there are definitely problems with our CRS which we acknowledge in issue #13. I would say that this issue is the duplicate of it.

The thing is that when I loaded those data in QGIS, everything works as expected in terms of CRS. So I am not aware where is the problem. :|

UPDATE:

I don't understand why the coordinates differ after any kind of export in comparison to values from QGIS which seems to be correct.

jvangeld commented 4 years ago

Skoda, are you using MapBox to generate tiles? Or are you bringing the shapefiles in as vector data?

Skoda091 commented 4 years ago

Skoda, are you using MapBox to generate tiles? Or are you bringing the shapefiles in as vector data?

No, I am just importing shapefiles to Postgis.

Finally, I've been able to solve the coordinate system problem. Using QGIS 3.4 I converted each layer from EPSG:32631 to EPSG:4326 and now I am able to correctly render those layers using leaflet.js. ;)

hellricer commented 4 years ago

That's great to hear! Did you try to play with qgis2web plugin for QGIS 3.4?

It generates leaflet maps and even tries to imitate your styles from qgis. But with all the data displayed at once it gets pretty sluggish.

I would love to find a way how to produce vector tiles from qgis.