function GetAlphamaps (x : int, y : int, width : int, height : int) : float[,,]

Description

Returns the alpha map at a position x, y given a width and height.

The returned array is three-dimensional - the first two dimensions represent x and y coordinates on the map, while the third denotes the splatmap texture to which the alphamap is applied.

// Add some random "noise" to the alphamaps.
function AddAlphaNoise(t: Terrain, noiseScale: float) {
    var maps = t.terrainData.GetAlphamaps(0, 0, t.terrainData.alphamapWidth, t.terrainData.alphamapHeight);
        for (var y = 0; y < t.terrainData.alphamapHeight; y++) {
            for (var x = 0; x < t.terrainData.alphamapWidth; x++) {
                 var a0 = maps[x, y, 0];
                var a1 = maps[x, y, 1];
                
                a0 += Random.value * noiseScale;
                a1 += Random.value * noiseScale;
                
                var total = a0 + a1;
                
                maps[x, y, 0] = a0 / total;
                maps[x, y, 1] = a1 / total;
            }
        }
        
        t.terrainData.SetAlphamaps(0, 0, maps);
    }