How can I import cotourlines in QGIS without losing the altitude data?

I have been having troubles while working with QGIS and trying to make the contourlines’ labels visible for the maps that I make for my projects.

The contourlines have their own altitude information when they are builded in PIX4DSurvey. When I export this information and then import it in QGIS than I can see the cotourlines, but their metadata get lost and the labels are not possible to be shown on the map.

Could somebody suggest any solution for this please?

Hi Aaron,
Yes, the contour lines that are exported from PIX4Dsurvey do not have the elevation data written in the attribute table. The data is contained as Z values in the vertices of the line. What you need to do is to extract that data and add it to the attribute table. I’m not as familiar with QGIS as I am with ArcGIS but there should be a tool that Adds Z Information. Once the data is added then you can label your contours.