geoAzimuthalEqualArea not rendering straight lines
fromdusttilldawn opened this issue · 2 comments
Hi
I made a map of Europe, where Russia and Turkey are still visible, but only to a certain degree. Using mapshaper I clipped the rest of those countries. The map looks like this when applying the command -proj laea (yes, I'm aware that Norway and Finland are clipped too much):
Now I'd like to render that map using the geoAzimuthalEqualArea projection from d3-geo. I use the projection like this (no extra settings):
geoAzimuthalEqualArea()
Why are the features on top and the right curved like that? Am I missing something?
Thanks already for any inputs or tips.
This works as expected. Mapshaper has clipped the shapes in planar coordinates, and connects consecutive points on the edge with no intermediate points. d3-geo then does great circle interpolation between those points (so parallels become “curves”), and furthermore along a projection that doesn't convert meridians to straight lines (so meridians also become “curves”).
Instead of mapshaper, you could try to use d3.geoProject to do the projection + rectangular clipping. See https://observablehq.com/@recifs/project-and-clip for an example.
I'll gladly have a look at those Observables. Thank you so much!