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Split elevation data needed for contour lines and 3D terrain/hill shading from map data #8672
Description
- Elevation data (even detailed contour lines without hill-shading) takes a lot of disk/download space.
- Elevation data does not change frequently.
- Supporting a full 3D terrain model will require even more data.
- It can be downloaded together with map data, but as a separate file, so in terms of UX users will get it anyway (if agreed) on the first download (but the map should be downloaded first for a better first-time experience).
@newsch @pastk can you please link related comments/issues about how elevation data is stored now in mwms? Elevation is embedded into each/most features/roads, and contour lines are stored as geometry lines, right?
Activity
pastk commentedon Jul 10, 2024
Yeap, contour lines are just lines with
isoline_XXtype.There is a separate
altitudesmwm section which is used for routing (@vng knows better).(And some features have
ele=tag in the metadata.)patepelo commentedon Feb 13, 2025
Another user is giving feedback that Kenya is missing isolines, after investigation it's due to map data being already too heavy. It affects other coutnries such as Malasya apparently and it seems that it's also a reason for isolines being so low in definition in other countries.