I am prototyping an action RPG, and wanted to experiment a bit with height from the top down perspective. Traditionally, height in RPGs such as Zelda: aLttP used pixel art to give the illusion of height, when actually all it was really doing was setting a collision, and making it look like it was a hill. What I am looking for is a system where the game actually allows the player to access different heights from a top down perspective.
Is there a way to efficiently implement such a system into this type of game? I thought about assigning each object with a height, and then instead of checking to see if the player is colliding with a certain object - it checks to see whether the players height is the same as the object. If it is then it can walk over it (Its on the same level), but if the objects height is higher than the players at that present time, then a collision occurs and the player cannot move in that direction. However my GML experience isn't exactly amazing and I kind of hit a wall when trying to get something like this working.
The reason I ask was that I would like to try and implement an element of destructible terrain into my action RPG where the player can add / delete blocks to give the impression of digging / building. The ground level would be a height of 0, and then the player could perhaps build or access up to 2 more levels above ground level.
Anybody have any thoughts or ideas on the subject?
Thanks in advance