Set the Units of a QgsGeometryGeneratorSymbolLayer object in PyQGIS

Question

I am pretty much following the procedure of this answer but I can't get my head around as to where to set the 'Units' from 'Map Units' (default) to Millimeters that is.

So far, I tried several variants to define a unit type and set the symbol layer to it:

millimeters = QgsUnitTypes.DistanceUnit.Millimeters
renderer().symbol().symbolLayer(1).setUnits(millimeters)

Answer 1

You have to use QgsUnitTypes.RenderMillimeters.

layer = iface.activeLayer()

mm = QgsUnitTypes.RenderMillimeters
layer.renderer().symbol().symbolLayer(1).setUnits(mm)

symbolLayer(1) must be an instance of QgsGeometryGeneratorSymbolLayer.

You can find different unit types in source code.