You can use the SurfaceDraper for that.

Yes, I tried that, I think I'm making a mistake. How should the settings and connections be?

If you want, I can share my data with you.

Your raster TIFF should go in the Points/Lines port, the points you want to get Z value for should go into the Drape Features and then the Surface Tolerance parameter is one of those mysterious things that even after reading the Help I’m not exactly sure what it does. If you enter 0 it will simply not filter out any points so let’s go with that for now.

It is of course important that your raster and points are in the same coordinate system, so you need to reproject if they’re not.

Thank you very much for your answers but I still get errors. Can you help me if I send you my data with fme workbench?

What kind of z-values are you expecting to see? Like, where I live, an elevation of 0.27 is a perfectly valid value.

They are not all at the same height, the region varies between 50/100 on average.

What are the Z units of the coordinate system you projected to? 

I am new so I could not understand your answer clearly but I introduced EPSG:3857 as the coordinate system so that both data are in the same system.

EPSG:3857 is a Spherical Mercator projection, using meters as units.

There could still be a lot of other issues here and with what you’ve shared so far it’s hard to pin down.

• What coordinate system(s) is your source data in (and if they’re the same, there’s no need to reproject)
• Which of the 3 CoordinatExtractor transformers you have in your workspace is that z attribute coming from that you’re pointing to?