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I am trying to center the Natuarl Earth 10m on the Pacific. I have followed instructions from QGIS Tutorial: How to Change the Map Projection to be Centered Over the Pacific Ocean.

When I change projection to EPSG:3832 the map in QGIS becomes fragmented:

enter image description here

How can I fix this? Do I need to define my own CRS entry?

I have seen other replies here Displaying world country shapefiles centered on Pacific Ocean using Robinson or Miller Cylindrical projection in QGIS? but that is 7 years old.

This is an edit: Interestingly open street map seems to reproject to 3832 ok. Slow and blurry though.

enter image description here

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  • A nice question, I am getting the same issue with other data, so it has nothing to do with Natural Earth Data. Did you try the solution from @AndreJ? I may suggest making a copy of the WGS 1984 World Mercator and editing the Central Meridian property. Check this thread as well Appropriate map projection for the Pacific Ocean.
    – Taras
    Aug 18 '20 at 5:32
  • I can't follow the solution from @AndreJ I guess QGIS 3 has a very different interface so I'm just guessing what should happen. NE 10 is already WGS84 as far as I can tell, I can't see how to disable on the fly projection, there's no option to use a semicolon separator, I don't see a very thin polygon - so I'm not even sure the first five steps are working. I'll have to dig deeper into your suggestions because atm I don't know enough to understand what they mean. But thank you for your comments. Aug 18 '20 at 6:00
  • look under custom delimiters for the option to set the ; when importing the file - all the other steps are fine
    – Ian Turton
    Aug 18 '20 at 7:36
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Artifacts are caused by the polygons that crosses the antimeridian, which for your projection is defined at -30 degrees.

Therefore you must find a way to create a polygon centered at -30 degrees, with a thin thickness.

Just to show another way to do it:

  • Create a new temporary scratch layer, of Linestring type, defined in geographic coordinates, and digitize a simple line with the approximate location of the -30 degrees meridian. Enable vertex editing and enter the exact coordinates of each of them:

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  • Save the changes to the temporary layer and perform a buffer of a small (in degrees) size to the line layer. You can use any small numer for the radius, like 0.00001.

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  • Lastly, perform the difference between the Natural Earth Layer and the Buffered layer. Now you can reproject the map to EPSG:3832:

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Notes:

  • The geometries coordinates are being preserved as geographic coordinates, reprojected only on the fly to the map canvas.
  • Remember that a Mercator projectio projects to infinite the poles.
  • The way to disable on the fly reprojection, in QGIS 3, is selecting "No projection" in the CRS tab of the project properties. It is not necessary for this Mercator projection.
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    That's beautiful man. Thanks Gabriel Aug 20 '20 at 1:49

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