

For OSM, such chunk storage might be considered a rendering. It could be akin to “converting” an SVG file to a GIF, with whichever anti-aliasing choices.
The most basic building block of OSM, the node, has only longitude and latitude. Few objects are tagged with ele or height, or other vertical tags (e.g. layer, building:levels, covered, incline, embankment, support).


https://youtu.be/XuwTUypO6eQ features a Juno Tab 4 with “Car Navigation”.