What is this guy thinking???
A game that led me into the realm of tech art is Valheim (Thank you, Iron Gate studio!), where I played for hundreds of hours. A game-changing mechanic in the game was that whenever I create a new world, the world feels completely different. From that time on I decided, I want to make games that you run a completely different adventure every time you click play.
There...I got into the world of random map generation (logically)and got a prototype for a 2D top-down map—with a newly written Wave Function Collapse(WFC)!
How to do a WFC?
I know this is just a very very simple prototype of WFC generation, but I will try my best to summarize its function here:
When you hit generate, you will get a map with your desired size (not necessarily square), with terrain types in the library. Right now, my library contains:
Grass, can be next to anything
Ice, must be adjacent to another ice block (no singular ice in other words)
Water, can only be adjacent to grass / ice, not desert
Then you will see the loading bar flicker, and a world map is on your screen, ta-daaaa!!!
To summarize what a WFC does, it at first generates all possibilities in all grids, making every grid happy. Then my code will choose several locations (4 in the gif) to start collapsing this giant map. Then it finds the lowest entropy on the grid (FYI the grid with lowest number of choices remaining) then select a random terrrain to place it there. This continues until all grids get collapsed. Then a random shape (of size 25 now) will start to cover every grid at random order to break down the map into smaller subdivisions.
The order goes like:
Initializing Board
Start Placing Initial Tiles
Collapsing Until Stable
Bringing in Broken-up Grids
Second Round of Collapse
Cleanup
Advantage of WFC and how it can work out
First, WFC is not costly...that means a lot! You dont have to iterate through all the points on a perlin noise map or check the value of every pixel point to get a simple job done. In my another article, I talked about perlin generation, and honestly, some tasks are as heavy as O(n^5), not even joking. The loading time is long enough I can take a nap.
Second, WFC is easy to manage. You can simply add an entry in your terrain library and then get something different: try adding a forest with its rules; you do not have to rewrite the whole algorithm.
Third, WFC is not hard to code as it is like Carcasonne the board game. EVERYTHING in this blog is written by blueprint, unbelievable as it seems. Depending on your language preference, you can choose any language you have on hand to have this map done.
Fourth, WFC takes any shape and any exception into account. Well, to be fair, as a Map-gen nerd, I have seen too many edge detection disasters while doing perlin (now I know why people like infinite world in MC). But in WFC, you can take in a shape of a cube and it will still work just fine. In fact, I did not write any edge detection, as long as the map can continue collapsing
Nontheless, there is one thing easier done with perlin: river! At first I tried to make rivers for the map as a personal interest. But then i figured out...rivers must be directional right? I then fell into a dungeon fighting river monsters and solving the Carcasonne river puzzles (it was fun by the way)
What can we do with WFC? Whats next?
A faraway dream for me is to make my RPG survival game with a WFC function. Why? You can have a lot of customizations in your world, making your adventure different every single time. Replayability, says game designers.
A shorter insight into this is about how AI can influence world-building. I know AI is heavily unstable, but how about giving AI a chance to manage the terrain library and possibilities? Or simply let AI take over our seeded random number generator (PRNG)? This can be something.
"An ominous, shapeless mass constantly weighs down on my heart."--Motojiro, Kajii
By making a random map, we can place the library of NPCs into the map also randomly. Factions, questlines, gamestyle...you name it! At least to me, my second favorite game Kenshi gave me countless possibilities everytime I play or see a streamer play. As a travel lover I am usually excited by thinking of the uncertain things that are gonna happen, why not making my game feel the same.
