Please Help Explain This Code

I’m trying to figure out this line of code. Please help me point out what is “.a” mean on this line of code.

craterData[x*cratertex.width + y].a

The full Code is below:

var saved : float[,,];
private var tData : TerrainData;
var cratertex : Texture2D;
var craterData;
var xRes: int;
var yRes: int;
var layers: int;
 
function Start () 
{
    tData = Terrain.activeTerrain.terrainData;
    yRes = tData.alphamapHeight;
    xRes = tData.alphamapWidth;
    layers = tData.alphamapLayers;
    craterData = cratertex.GetPixels();
    saved = tData.GetAlphamaps (0, 0, xRes, yRes);
}
 
function OnApplicationQuit () 
{
    tData.SetAlphamaps (0,0,saved);
}
 
function Update () 
{
    if (Input.GetMouseButtonDown(0))
    {
       var g : int = Mathf.Lerp(0, xRes, Mathf.InverseLerp(0, tData.size.x, mouse.mousepos.x));
       var b : int = Mathf.Lerp(0, yRes, Mathf.InverseLerp(0, tData.size.z, mouse.mousepos.z));
       g = Mathf.Clamp(g, cratertex.width/2, xRes-cratertex.width/2);
       b = Mathf.Clamp(b, cratertex.height/2, yRes-cratertex.height/2);
       var area = tData.GetAlphamaps(g-cratertex.width/2, b-cratertex.height/2, cratertex.width, cratertex.height);
       for (x = 0; x < cratertex.height; x++) 
       {
         for (y = 0; y < cratertex.width; y++) 
         {
          for (z = 0; z < layers; z++)
          {   
              if (z == 1)
              {
                 area [x,y,z] += craterData[x*cratertex.width + y].a;
              }
              else
              {  
                 area [x,y,z] -= craterData[x*cratertex.width + y].a;  
              }  
          }
         }
       }
       tData.SetAlphamaps (g-cratertex.width/2,b-cratertex.height/2,area);
    }
}

it’s very easy to solve problems like this by looking at the documentation

Note that when you make the “craterData” you use “GetPixels”

So go to the doco:

what does GetPixel return? A “Color”

So go to the doco:

You now have your answer … it’s the alpha value. OK? If you have further questions post 'em.