Hi @ahpierre
If you are using FME 2022 or later, try setting "Clip Original Candidates" to the Overlapping Clippers parameter.
You might be able to do something with the AreaOnAreaOverlayer. I have created two building features: 
As you can see they overlap. I have also created a vegetation feature:
I put them in the AoAO with these settings:
This is the result, note that the ID list I have created is not yet visible in the Visual Preview window:
I then put this through the ListExploder (where List Attribute = _id_list{}), which gives me this:
The red part is output through the <Rejected port>. This feature has no overlap with a building, and thus no _id_list{} attribute.
The Elements port is of interest, since this contains all parts of our building features. More specific, the features in the Elements port where the Vegetation attribute has a value is of interest to us! These are our building features that overlap with a vegetation feature.
We can use a Tester to filter out the parts that do not overlap with a vegetation feature and dissolve grouped by the building id. We now have the (complete) parts of our building features that overlap with vegetation. You can use AreaCalculator to calculate area:
Maybe I should have made another vegetation feature, since nearly all our building features overlap entirely with the vegetation feature..
This is the workspace I used:
That's a good idea. But it still results in missing data in the output.
You might be able to do something with the AreaOnAreaOverlayer. I have created two building features: As you can see they overlap. I have also created a vegetation feature:
I put them in the AoAO with these settings:
This is the result, note that the ID list I have created is not yet visible in the Visual Preview window:I then put this through the ListExploder (where List Attribute = _id_list{}), which gives me this:
The red part is output through the <Rejected port>. This feature has no overlap with a building, and thus no _id_list{} attribute.
The Elements port is of interest, since this contains all parts of our building features. More specific, the features in the Elements port where the Vegetation attribute has a value is of interest to us! These are our building features that overlap with a vegetation feature.
We can use a Tester to filter out the parts that do not overlap with a vegetation feature and dissolve grouped by the building id. We now have the (complete) parts of our building features that overlap with vegetation. You can use AreaCalculator to calculate area:
Maybe I should have made another vegetation feature, since nearly all our building features overlap entirely with the vegetation feature..
This is the workspace I used:
That's a good approach - I will give it a try. In theory it works better than the approach I had in mind as first, so thanks a lot.
