Transitioning different terrain noise data between tiles

Castle terrain noise data produces nice terrain in small areas, but over large areas it starts to look endlessly repetitive. So now I have made it so each terrain tile can have different castle noise data. To prevent ugly transitions I use 25% of the tile as a transition zone where it mixes its noise with that of its neighbor. Now you can have a large mountain range that comes to a flat area. All the water flows out to the flat area.

There can be any number of noise definitions, given a name like ‘mountain’ that it can work from. This way there could be macro map that treats each tile as a ‘pixel’ that has many data values like terrain type, or an underlying macro elevation.

Here we have ‘mountain’ and ‘flat’ with all tiles with x<0 set to flat. It makes the transition line really long and straight but is pretty smooth transition.

Here the tiles randomly are ‘mountain’ or ‘flat’… the result is a nice mix of mountain and more open valleys.

You can see the grid more with these large square areas of different noise. It might be cool to make the transition zones less of a straight line.

Making the transition area 1/3 of a tile makes it look like the number of tiles is higher as the transition areas are the same size as the middle. This looks better. Note that I am not transitioning the tile corners yet, so you see some discontinuity at the tile corners.

Damn transitioning those corners to match both neighbors’ corners is hard to figure out. Like a 3 body problem. You figure out the corner of one tile, but then that affects both neighboring tiles (whether they are the same noise or different). Some corners you compare to, that tile is already built and its corner transitioned, sometimes that tile isn’t yet and you look at the data its noise would produce, but you don’t know how it will end up transitioning. I have gone around in circles and broke my brain. I will have to go back to other things or go mad. A variety of terrains maybe is not so important. Here are the tiles alternating checkerboard style between mountain noise and flatland noise.

Maybe it would be better to have entire transitional tiles that mix all the neighboring terrain noise sources based on the location of the vertex in the transition tile. This might be a lot easier and cleaner. The results should be smoother, look less griddy and not have the corner difficulties. Hmm, maybe then all tiles are transitional and affected by their different neighbors. I think that might produce good results.