I think I did something on auto-tiles before, but I’ll explain how they work so you could make your own. This is for RM2k3.

rm2k3auto1

These are from the RM2k3 RTP. I didn’t make them but they’ll be good to use.

The top 3 are the auto-tiles, and the row on the bottom is the first row of the auto-tiles.

rm2k3auto2

There are 3 tiles in a row. The first one is circled here. Basically, this tile doesn’t show up on the map but is used as a reference.

The 2nd tile shows what terrain it’s based off of. So, in the snow ground, it is surrounded by grass, so I post the 1st tile of the grass auto-tile there. For the snow forest, we don’t want the grass to be around it, but rather the snow. So, post the 1st tile of the snow auto-tile there.

The 3rd tile here is for the corners. I’ll go over this in a bit.

rm2k3auto3

For making the auto-tile, there is a 48×48 space for it. Each tile is 16×16 pixels, so I would set a grid to that. So there’s the corner tiles, the side tiles that can extend out, and the center tiles which you want to make sure tile correctly. I posted a few examples there.

rm2k3auto4

The 3rd tile on the first row is for connecting corner pieces together. I set up the corner pieces like in #1. Then I put a center tile piece in the middle of the 2 as shown in step 2. Then, make the connection. The connection part shouldn’t be more than 8×8 pixels. There are 4 8×8 pixel pieces for the 3rd tile in the 1st row. I posted a 3x version of it on the bottom. Sometimes you can just get away with placing a corner tile up there, like how they did with the ice forest.

If there’s anything here you’d like me to go over more or show more examples of, feel free to let me know!