thanks, this seems to be what i am looking for. although i work in 3d there are similar functions. however i don't understand how i can get this to work. the area function requires a collision mask. collision masks are only available for rigid bodys and so on, not for collision shapes. a collision shap however is the node that defines the area of the area node.
so: my area not has a child that is a collision shape. but this needs to be a collision object? how can a collision object define the area of my area node?