I think you're overthinking this.
How are the instance ids of the transition correlated with the rooms?
Basically, when you enter your main room, you want to destroy one instance matching the previous room? As in, there is a one-to-one relationship between rooms you could be coming from and instances you could be destroying?
In that case, just set
Code:
// Room End Event
global.previous_room = room;
in any Room End event, then put directly into the Room Start event of the transition object
Code:
// Room Start Event
if (target_room == global.previous_room) instance_destroy();
Thanks for the answer but I have a few questions and answers to give you ^^
First of all, like I mentioned, I think I complicated my question and it's hard to understand... So, I'll try to explain better:
As soon as the game itself begins, you have an rSelectionRoom. In this room, you have 4 objects that make you transition to four other rooms, each transition to a different one.
Now, you've went to a room, let's call it "Room1". When you finish Room1 another transition object is presented but this one will take you to the rSelectionRoom.
My objective in this was, when we get to rSelectionRoom after finishing Room1, the object that allowed you to move to Room1 was now destroyed. Not sprite replaced, or object replaced, just destroyed.
About the ids, I think the answer to it (by what I understand of the question) is that each object has a different transition location.
I don't understand you're second question... But if I explained myself corretly now,it might be a bit more clear.
You mentioned "in any Room End Event". Where exactly do I find this? Is this an object or the Room itself?
Once again, I thank you for your help!!