UnityEngine.Terrain.SetNeighbors C# (CSharp) Method

        public extern void SetNeighbors(Terrain left, Terrain top, Terrain right, Terrain bottom);
        /// <summary>

    // Use this for initialization
    void Start()
    {
        R = Instantiate(MainTerrain) as Terrain;
        R.transform.position = new Vector3(MainTerrain.terrainData.size.x,0,0);
        L = Instantiate(MainTerrain) as Terrain;
        L.transform.position = new Vector3(-MainTerrain.terrainData.size.x,0,0);
        T = Instantiate(MainTerrain) as Terrain;
        T.transform.position = new Vector3(0,0,MainTerrain.terrainData.size.z);
        B = Instantiate(MainTerrain) as Terrain;
        B.transform.position = new Vector3(0,0,-MainTerrain.terrainData.size.z);

        TR = Instantiate(MainTerrain) as Terrain;
        TR.transform.position = new Vector3(MainTerrain.terrainData.size.x,0,MainTerrain.terrainData.size.z);
        BR = Instantiate(MainTerrain) as Terrain;
        BR.transform.position = new Vector3(MainTerrain.terrainData.size.x,0,-MainTerrain.terrainData.size.z);
        TL = Instantiate(MainTerrain) as Terrain;
        TL.transform.position = new Vector3(-MainTerrain.terrainData.size.x,0,MainTerrain.terrainData.size.z);
        BL = Instantiate(MainTerrain) as Terrain;
        BL.transform.position = new Vector3(-MainTerrain.terrainData.size.x,0,-MainTerrain.terrainData.size.z);

        TL.SetNeighbors(null,null,T,L);
        T.SetNeighbors(TL,null,TR,MainTerrain);
        TR.SetNeighbors(T,null,null,R);
        L.SetNeighbors(null,TL,MainTerrain,BL);
        MainTerrain.SetNeighbors(L,T,R,B);
        R.SetNeighbors(MainTerrain,TR,null,BR);
        BL.SetNeighbors(null,L,B,null);
        B.SetNeighbors(BL,MainTerrain,BR,null);
        BR.SetNeighbors(B,R,null,null);
    }