[Scripting Question] How do you change The Overworld's Loaded TileSets via Script?

[SuperSpyroDragon64]

Remember how the Sinnoh Underground mirrored the overworld? I had this idea for a "Dimension Changer" Key Item that changes the TileSet of all overworld maps when activated, making them all load TileSet Number 69. Use the item again, and it switches back to TileSet 25.

Is this possible in the Pokemon Essentials Engine? I know I can alter a switch to make normal NPCs invisible and load in NPCs who are only supposed to show up in the changed dimension. That part's already working in my game. But dynamically changing tileset on the fly via script... I don't know if that's possible. Is it possible?

Or would I need to make a separate copypaste of the entire game's region with the tileset changed, and change the Dimension Changer to an overworld object in each Pokemon Center that will warp you between the main world and tileset-changed world?

 

[burningplain]

Short answer is yes. In the script section called Game_Map, theres a portion that looks like this (should be around line 45):

def setup(map_id)
    @map_id = map_id
    @map = load_data(sprintf("Data/Map%03d.rxdata", map_id))
    tileset = $data_tilesets[@map.tileset_id]
    updateTileset

Add a couple lines to the script to make it look like this:

def setup(map_id)
    @map_id = map_id
    @map = load_data(sprintf("Data/Map%03d.rxdata", map_id))
    tileset = $data_tilesets[@map.tileset_id]
    if $game_switches[65] && @map.tileset_id = 1
     then @map.tileset_id = 3
    end
    updateTileset

The first map id is the original tileset, while the second is the new one, and the switch can be any switch you want.


The long answer is that this is both difficult and finicky to make work. First off, the code I wrote doesn't automatically update the map you are on, so the thing that triggers the switch should be somewhere that doesn't change (like inside a building or wherever). You could possibly find a way to make it refresh the tileset you are standing on, but I don't know what the command would be.
Second, when you change tilesets, you have to have every single tile in use and its counterpart on the same spot on the tileset. In my opinion, the easiest way to do that would be to start with a copy of the original tileset, then replace each tile out with its counterpart. This would guarantee that the tiles are in the correct spot when it switches.