So I'm trying to make a map with the Exterior tileset, and I made a bridge spanning across some water. However, when I do that, the bridge tiles automatically get this blurry shadow over the water to the right of them. I can't remove it with the Shadow Pen, and drawing over it looks stupid.
I noticed in one of the sample maps (Castle Town) there is a bridge across water but it doesn't have that shadow to the right of it, instead it has a shadow painted with the Shadow Pen.
That blurry on on the left is the autoshadow of the water tile itself. What's happening is that you are putting down a tile which the engine reads as being the equivalent of a ground tile, and so moves the edge of the water over.
What you will need to do is to put down the right hand edge tile of the bridge somewhere on your map where there is no other graphic, then shift-click map with it, then use the shadow pen to put in the shadow you want.
Is there also a way to get only the top and bottom edges of an autotile? As you can see in the image below, the pathway under the bridge looks like it stops at one edge of the bridge and continues at the other. But for a realistic effect that pathway shouldn't have edges at the point where they "collide" with the bridge.
someone feel free to correct me if I'm wrong, but the bridge tile isn't an autotile. The water tile can be pieced shift+click style and changed because the tile is actually made up of all this , but the bridge tile is just as it looks but the bridge tile is just as it looks. you can change the stone tile with the shift+click method and it might fix your issue though. like this http://puu.sh/ba8AN/3ae597773f.png