Simulate depressurization in a discrete room
I am trying to build a top down view spaceship game which has destructible parts. I need to simulate the process of depressurization in case of hull breach.
I have a tiled map which has the room partitioning code setup:
What I am trying to do is build some kind of a vector field which would determine the ways the air leaves depressurized room. So in case you would break the tile connecting the vacuum and the room (adjacent to both purple and green rooms), you'd end up with a vector map like this:
My idea is to implement some kind of scalar field (kind of similar to a potential field) to help determine the airflow (basically fill the grid with euclidean distances (taking obstacles into account) to a known zero-potential point and then calculate the vectors by taking into account all of the adjacent tiles with lower potential value that the current tile has:
However this method has a flaw to where the amount of force applied to a body in a certain point doesn't really take airflow bottlenecks and distance into account, so the force whould be the same in the tile next to vacuum tile as well as on the opposite end of the room.
Is there a better way to simulate such behavior or maybe a change to the algorithm I though of that would more or less realistically take distance and bottlenecks into account?
Algorithm upgrade ideas collected from comments:
(...) you want a realistic feeling of the "force" in this context, then it should be not based just on the distance, but rather, like you said, the airflow. You'd need to estimate it to some degree and note that it behaves similar to Kirchoff rule in electronics. Let's say the hole is small - then amount-of-air-sucked-per-second is small. The first nearest tile(s) must cover it, they lose X air per second. Their surrounding tiles also must conver it - they lose X air per second in total. And their neighbours.. and so on. That it works like Dijkstra distance but counting down.
Example: Assuming no walls, start with 16/sec at point-zero directing to hole in the ground, surrounding 8 tiles will get 2/sec directed to the point-zero tile. next layer of surrounding 12 tiles will get something like 1.33/sec and so on. Now alter that to i.e. (1) account for various initial hole sizes (2) various large no-pass-through obstacles (3) limitations in air flow due to small passages - which behave like new start points.
Another example (from the map in question): The tile that has a value of zero would have a value of, say, 1000 units/s. the ones below it would be 500/s each, the next one would be a 1000/s as well, the three connected to it would have 333/s each.
After that, we could base the coefficient for the vector on the difference of this scalar value and since it takes obstacles and distance into account, it would work more or less realistically.
Regarding point (3) above, imagine that instead of having only sure-100%-pass and nope-0%-wall you also have intermediate options. Instead of just a corridor and a wall you can also have i.e. broken window with 30% air pass. For example, at place on the map with distance [0] you've got the initial hole that generates flux 1000/sec. However at distance [2] there is a small air vent or a broken window with 30% air flow modifier. It means that it will limit the amount from incoming (2x500=1000) to 0.3x(2x500)=300/sec that will now flow further to the next areas. That will allow you to depressurize compartments with different speeds so the first few tiles will lose all air quickly and the rest of the deck will take some more time (unless the 30%-modifier window at point [2] breaks completely, etc).