Version: 2022.3
  • C#


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public float[,,] GetAlphamaps(int x, int y, int width, int height);


x The x offset to read from.
y The y offset to read from.
width The width of the alpha map area to read.
height The height of the alpha map area to read.


float[,,] A 3D array of floats, where the 3rd dimension represents the mixing weight of each splatmap at each x,y coordinate.


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.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { // Add some random "noise" to the alphamaps. void AddAlphaNoise(Terrain t, float noiseScale) { float[,,] maps = t.terrainData.GetAlphamaps(0, 0, t.terrainData.alphamapWidth, t.terrainData.alphamapHeight);

for (int y = 0; y < t.terrainData.alphamapHeight; y++) { for (int x = 0; x < t.terrainData.alphamapWidth; x++) { float a0 = maps[x, y, 0]; float a1 = maps[x, y, 1];

a0 += Random.value * noiseScale; a1 += Random.value * noiseScale;

float total = a0 + a1;

maps[x, y, 0] = a0 / total; maps[x, y, 1] = a1 / total; } }

t.terrainData.SetAlphamaps(0, 0, maps); } }