Create 3D-SHP / MIF from 2D-SHP and height attributes

Question

I have two .SHP-files:

1. Contains building footprints as polygons with IDs in the attributes
2. Contains building height attributes (+ other information not relevant for me) as points with the same IDs in the attributes

I want to combine the building footprints with the height information to create a 3D-Shape or MIF/MID-file.

Is there a simple GUI-way for noobs like me or do I have to do some fancy Python stuff?

Answer 1

This is achievable via the GUI in QGIS 3.0 (which isn't officially released yet, so you'll need to download a nightly/weekly prerelease version).

Steps are:

1. Join the two shapefiles together, so that the attributes (including the height) from your point layer are added to the polygon layer. This assumes that the two layers have some unique ID field in common, which can be used to join them. The "Join attributes table" algorithm can be used to perform the join.

2. Using the "Set Z Value" algorithm, you can turn the height attribute into real 3d geometries with a z value matching this attribute. You need to run this algorithm over your joined polygon layer, by clicking the drop down next to the "Z Value" parameter and picking the field containing your building heights.