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# Cave generation using cellular automata unexpected results 1
So I've been implementing a cave generating algorithm for a game that I'm working on. I'm using a cellular automaton for this algorithm but I've been facing some problems, it doesn't seem to be working properly. About the cellular automaton I'm using the following rule i found on a website:
Clouds 1 rule: 13-26/13-14,17-19/2/M
Alive cells with 13,14,15,16,17,18,19,20,21,22,23,24,25 or 26 neighbors survive. Empty cells with 13,14,17,18 or 19 neighbors have a new cell born at that location. 2 states. Cells are either dead or alive. No refractory period they fade from birth to death. M means a Moore neighborhood.

About Moore neighborhood : consider a 3x3x3 3D grid of little cubes. The interior cube is the current cell, so the remaining 26 cubes around it are the neighbors of the center cube.

Is there anything that I'm doing wrong? It's not giving me the expected results.

And by the way here is the code i used to generate the caves :

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1. int cellular_iterations = 50;
2.
3. srand((ax * CX) + (ay * CY) + (az * CZ));
4. for (int x = 0; x < CX+2; x++)
5.     for (int y = 0; y < CY+2; y++)
6.         for (int z = 0; z < CZ+2; z++)
7.         {
8.             float rd = (float)rand() / (float)RAND_MAX;
9.             if (rd > 0.5f)  cellules[x][y][z] = 1;
10.             else    cellules[x][y][z] = 0;
11.
12.             if (ay == (-SCY/2)) cellules[x][y][z] = 1;
13.         }
14.
15. std::vector<std::vector<std::vector<int>>> cellules_(CX + 2, std::vector<std::vector<int>>(CY + 2, std::vector<int>(CZ + 2, -1)));
16. for (int i = 0; i < cellular_iterations; i++)
17. {
18.     for (int x = 1; x < CX+1; x++)
19.         for (int y = 1; y < CY+1; y++)
20.             for (int z = 1; z < CZ+1; z++)
21.             {
22.                 bool isalive = false;
23.                 int alive_blocks = 0;
24.                 for (int x_ = -1; x_ < 2; x_++)
25.                     for (int y_ = -1; y_ < 2; y_++)
26.                         for (int z_ = -1; z_ < 2; z_++)
27.                         {
28.                             if (!(x_ == 0 && y_ == 0 && z_ == 0))
29.                             {
30.                                 alive_blocks += (cellules[x+x_][y+y_][z+z_] == 1) ? 1 : 0;
31.                             }
32.                             else
33.                             {
34.                                 if(cellules[x + x_][y + y_][z + z_] == 1)   isalive = true;
35.                             }
36.                         }
37.                 if (isalive && alive_blocks >= 13)
38.                 {
39.                     cellules_[x][y][z] = 1;
40.                 }
41.                 else if (!isalive && ((13 <= alive_blocks && alive_blocks <= 14) || (17 <= alive_blocks && alive_blocks <= 19)))
42.                 {
43.                     cellules_[x][y][z] = 1;
44.                 }
45.                 else
46.                 {
47.                     cellules_[x][y][z] = 0;
48.                 }
49.             }
50.     for (int x = 0; x < CX + 2; x++)
51.         for (int y = 0; y < CY + 2; y++)
52.             for (int z = 0; z < CZ + 2; z++)
53.             {
54.                 cellules[x][y][z] = cellules_[x][y][z];
55.                 if (ay == (-SCY/2)) cellules[x][y][z] = 1;
56.             }
57. }
58.
Dec 18 '20 #1
1 1245 Rabbit
12,516 Expert Mod 8TB
You need to create the next generation into a new array. Right now, you're using the state of cellules to update itself, changing its state.
Dec 18 '20 #2