Hfrhyu

I am trying to add elevation to a 2D point in a QGIS 3 plugin, preferably in a concise and straightforward way. Not finding this easy.

I think part of the problem is that in QGIS 3, fromPoint() has been renamed to fromPointXY(). I am not very clear on how to create 3D point geometry.

I have tried a number of variations without finding one which works and have not been able to find a suitable example online.

Basically what I want to achieve is PointXY + elevation -> Point, which I would expect to be something like this:

z = 1.0 # or whatever

for l in selectedLayers: # for each selected layer
 if l.geometryType() == QgsWkbTypes.PointGeometry: # point layer

 l.startEditing()
 feat = l.getFeatures()

 for f in feat: # each feature

 # Get existing geometry...
 geom = f.geometry()
 pt = geom.asPoint() # returns PointXY

 # Replace with 3D geometry...
 pt3D = QgsPoint(pt.x(), pt.y(), z)
 geom = QgsGeometry.fromPointXY(pt3D) # error, because pt is 3D
 f.setGeometry(geom)

 l.updateFeature(f)

 l.commitChanges()

How do I do this?

For the benefit of others this is now resolved using the answer(s) below.

I am now adding the elevation like this:

f.setGeometry( QgsPoint(pt.x(), pt.y(), z) ) # x, y, z

It turns out that my problem was not so much adding the elevation, as knowing when I had successfully added it.

You don't need create a QgsGeometry object.

Add minimal sample for setGeometry 3D

feature = QgsFeature()
feature.setAttributes([lon, lat, alt])
feature.setGeometry(QgsPoint(lon, lat, alt))
layer.addFeatures([feature])

The original code is in my github,where a lot of layers are in 3d

https://github.com/All4Gis/QGISFMV/blob/35eb3f59b4d6423a375d7a04d54b6765dcc5c986/code/utils/QgsFmvLayers.py#L515

And for get to z value from feature,you can use something like that:

feature.geometry().vertexAt(0).z()

If you are looking at the Geometry of a feature you will have to do something like:

val_x = geom.get().x()
val_y = geom.get().y()
val_z = geom.get().z()

How to get the Z values of existing lineStringZ with pyqgis?