Backdrop scope of invisible objects

[troglodyte111]

I think there is a problem with backdrop scopes of invisible objects. When I am in the room of the invisible object all is as expected (it is not listed in the description and I cannot do anything with it). When I am in a room where that object is given as a backdrop scope (in the game advanced scripts) it is still not listed in the description BUT I can examine it. I can even get it, resulting in "you pick it up". When I then do "inventory" it is not listed, and I cannot drop it ("you are not carrying it"). Spooky.
Is this a bug or did I misunderstand something?
A workaround is to add the backdrop in the game advanced scripts only if the object is visible.

[angelwedge]

I'm not sure what the issue is here. That sounds like intended behaviour to me.

The backdrop scope script allows you to override Quest's standard system for determining which objects a command can be used on. Because you're already overriding the default behaviour, the standard code can't second-guess what you're trying to do. It trusts you to do any necessary checking of the items list, and allows the player to use commands (except those that are inventory-only) on any of the objects you have added.

Room descriptions list visible objects in the current room, and the inventory lists visible objects in the inventory; neither of them is changed by adding an object to scope.

I will agree that the "drop" behaviour seems slightly counterintuitive. This is because the backdrop scope script doesn't affect commands whose scope is "inventory". Maybe there should be a corresponding script that does work on the inventory? You can do that using changecommandscope, but that's maybe not the ideal solution.

If you don't want to let the player interact with invisible objects, don't add them to the list in your backdrop scope script. If you do, there are a couple of options. I would suggest that you could modify either the take script, or the object's changedparent script, to make them visible when picked up.

[troglodyte111]

Thanks. What you say makes sense.
I always though of backdrops as adding to scope and invisibility as removing from scope. In that interpretation it is unclear in which order this happens. So it is not the correct way to think about it. I'll take your advice not to backdrop invisible objects.