Simple terrain texture chaging - help

Ok, so i've done a very small and straightforward script that should go through all points in the alpha map of my terrain and change the texture according to the y coordinate, but it isn't applying the third texture and the axis are switched for some reason.
It should be something like: Stone, grass, snow but instead its what is on the image. Help!

Code (CSharp):

1. using UnityEngine;
2.  
3. public class Biome : MonoBehaviour
4. {
5.  
6.  
7.  
8.     // Use this for initialization
9.     void Start()
10.     {
11.     Terrain thisterrain = Terrain.activeTerrain;
12.     TerrainData td = Terrain.activeTerrain.terrainData;
13.     drawTextures(thisterrain, td);
14.  
15.     }
16.  
17.     void drawTextures(Terrain thisterrain, TerrainData td)
18.     {
19.         var alphaData = td.GetAlphamaps(0, 0, td.alphamapWidth, td.alphamapHeight);
20.  
21.         for (int x = 0; x < td.alphamapWidth; x++)
22.         {
23.             for (int y = 0; y < td.alphamapHeight; y++)
24.             {
25.                 if (y < 400)
26.                 {
27.                     for (int k = 0; k < td.splatPrototypes.Length; k++)
28.                     {
29.                         alphaData[x, y, k] = 0;
30.                     }
31.                     alphaData[x, y, 1] = 1;
32.                 }
33.  
34.                 else if (y < 1400)
35.                 {
36.                     for (int k = 0; k < td.splatPrototypes.Length; k++)
37.                     {
38.                         alphaData[x, y, k] = 0;
39.                     }
40.                     alphaData[x, y, 0] = 1;
41.                 }
42.  
43.                 else
44.                 {
45.                     for (int k = 0; k < td.splatPrototypes.Length; k++)
46.                     {
47.                         alphaData[x, y, k] = 0;
48.                     }
49.                     alphaData[x, y, 2] = 1;
50.                 }
51.  
52.             }
53.         }
54.         td.SetAlphamaps(0, 0, alphaData);
55.     }
56. }

 

My first guess would be your conditions (y < 1400) are not correct - in this case too big. Therefor texture 3 just never happens. You are cycling through the x and y coordinates based on the alphamapWidth and Height, but using fixed numbers on your conditions.

 

Yep thanks on that, i was changing wrong settings to 2048... about the x and y of the alpha map, shouldnt they be equal to the x and z of the scene? respectively