I want to create a simple, custom projection in proj4. I need it to be completly flat ( rectangular coordinates ). Starts in point (0,0), meters as unit, everything else - as simple as possible. What parameters my definition should have to achieve it?

Am I even able to do it? Ignoring the curvature of the Earth?

  • 2
    It might help if you can explain what you are really trying to achieve ("why"). In general, we use proj to transform and project points. What would a meaningful conversion look like in your case? I'd guess you are just looking for a false easting and false northing of 0,0.
    – BradHards
    Mar 25, 2019 at 9:51
  • I need a projection for fictional, flat world (not real one), but I still want to be able to use all GIS tools, so I want a proper coordinate system somehow defined
    – Mativane
    Mar 25, 2019 at 10:01
  • 1
    So you don't really want to project it, you just want a coordinate system (EPSG number or similar) works in your tools? If so, its sometimes called an engineering coordinate system - epsg.io/5806 is an example, epsg.io/5807 is in metres if that helps.
    – BradHards
    Mar 25, 2019 at 10:06
  • Perhaps you are right, as I'm not very experienced in that matter. Is there any place where I can read more about engineering coordinate systems in general?
    – Mativane
    Mar 25, 2019 at 10:17
  • @Mativane did you resolve this? I would also need a "flat earth" projection for my fantasy mapping needs. Aug 18, 2021 at 10:46

1 Answer 1


Try to use custom EPSG code (starting from 10000 number) and this definition (with a=0 and b=0):

+proj=merc +a=0 +b=0 +lat_ts=0 +lon_0=0 +x_0=0 +y_0=0 +k=1 +units=m +nadgrids=@null +wktext +no_defs

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