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I try to measure specific points and extract the x-, y-, and z-coordinates to a table which I later can export. Further I want to give each point an automatically generated id. By creating a new vector layer for the points, it is no problem to add the x- any y- coordinates to the attribute table using the field calculator ($x and $y), but I can't find a way to extract z-coordinates from a dtm into that list. I converted it to a shapefile but still wasn't able to get the data.

Yes I tried that, but it only seemed to measure when I clicked at one of the generated points. Furthermore my Attribute table is quite huge due to the big DEM I use, which results in a Long loading time. In this case I would need a new table to generate the data in. Next question is what code is needed in the field calculator, because just $z isn't working...

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    Rave you tried add raster values to points? If so, what happens?
    – Erik
    Feb 5, 2020 at 13:21
  • Are you trying to create a point for each pixel in the DEM - which would benefit from a different approach to sampling as you first described? Feb 6, 2020 at 8:28

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Install the Point Sampling tool (via Plugins->Manage and Install Plugins) and use that. It samples the DTM at your point location (no need to convert the dtm).

Alternatively you can use the Drape tool from the processing tool box (or v.Drape in GRASS).

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