gistfile1.cs

    public IEnumerator AddTrees()
    {
        ClearTrees();
        int height = _terrain.terrainData.heightmapWidth;
        int width = _terrain.terrainData.heightmapWidth;
        float[,] heights = _terrain.terrainData.GetHeights(0, 0, width, height);
        float[, ,] map = _terrain.terrainData.GetAlphamaps(0, 0, width - 1, height - 1);
        Perlin perlin = new Perlin();
        perlin.Seed = seed;
        Noise2D noisePlane = new Noise2D(width, height, perlin);
        noisePlane.GeneratePlanar(0, 1, 0, 1);
        float[,] noiseData = noisePlane.GetData();
        System.Random rand = new System.Random(seed);
        int treesThisFrame = 0;
        int totalTrees = 0;
        
            trees = new List<Vector3>();

                for (int x = 0; x < width - 1; x++)
                {
                    for (int y = 0; y < height - 1; y++)
                    {
                        float Locheight = heights[x, y];
                        float mapVal = map[y, x, 0];
                        float noiseVal = noiseData[x, y];
                        /*if (x == y)
                        {
                            Vector3 treePos = new Vector3(x / (float)width, 0, y / (float)height);
                            TreeInstance ti = new TreeInstance();
                            ti.prototypeIndex = 0;
                            ti.heightScale = 1.0f;
                            ti.widthScale = 1.0f;
                            ti.color = Color.white;
                            ti.position = new Vector3(x / (float)width, 0, y / (float)height);
                            _terrain.AddTreeInstance(ti);
                            trees.Add(treePos);
                            treesThisFrame++;
                            totalTrees++;
                        }*/
                        if (mapVal == 1)
                        {
                            int treeScarcity = 100;
                            if (noiseVal >= 0 && noiseVal <= 1)
                            {
                                treeScarcity = 80;
                            }
                            else if (noiseVal >= 1 && noiseVal <= 2)
                            {
                                treeScarcity = 85;
                            }
                            else
                            {
                                treeScarcity = 90;
                            }

                            if (rand.Next(0, 100) >= treeScarcity)
                            {
                                TreeInstance ti = new TreeInstance();
                                ti.prototypeIndex = 0;
                                ti.heightScale = 1.0f;
                                ti.widthScale = 1.0f;
                                ti.color = Color.white;
                                ti.position = new Vector3(x / (float)width, 0, y / (float)height);
                                _terrain.AddTreeInstance(ti);
                                treesThisFrame++;
                                totalTrees++;
                            }
                            
                        }
                    }
                    if (x % 10 == 0)
                    {
                        Debug.Log("Added " + treesThisFrame + " trees this frame.");
                        treesThisFrame = 0;
                        yield return new WaitForEndOfFrame();
                    }
                }
                Debug.Log("Added " + totalTrees + " trees in total.");

    }