The Question:

Is there way to leverage GIS tools to author/edit a schematic map where elements' geometries has canvas-based coordinates rather than real-world coordinates on Earth?

Perhaps to achieve this, a special Coordinate Reference System (CRS) could be used; one that does "No Projection", one that maps an (X,Y) point directly as-is on a Canvas (instead of on Earth).


I'm maintaining a Geo-database feeding a real-world map. I'd like to also maintain, in parallel, a "schematic map" where I arbitrarily locate the same elements on a planner canvas. So while each element has a Geometry column with real-world coordinates, it also has another geometry column (point, line...etc) with simple X/Y canvas-based coordinates (not real-world) (similar to vectors in an SVG).

Then it would be of great value if I could view/edit this schematic map in GIS tools (like QGIS).


  • A Real-World Map, in one QGIS project, has layers of features using their typical geometry column in a typical CRS (say WGS 84) - this map is typical, no problems here!
  • A Schematic Map, in another QGIS project, has layers of the same features but using another geometry column that is canvas-based (rather than the real-world) coordinates.

Although the essence of GIS is to manage elements located on Earth (real-world coordinates), my special use-case would benefit highly from managing a schematic map in the same environment and with the same tools as a real one.

Any thoughts?

NOTE: I'm not trying to generate a schematic map automatically (like ArcGIS' Schematics extension does).

  • You could create a local grid CRS to use in any GIS. That would give you local/canvas based "coordinates" that can be translated to real world as they are define as a CRS. We use these for local mine grids defined by affine transformation, where things are measured verry locally. This approach is only really good for local not regional, due to precision errors. Sep 21, 2020 at 9:12


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