public void CompressData(ref byte[] data,int x, int y, int z, byte b) { int index = GetBlockIndex(x, y, z); if (index % 2 == 0) data[index/2] = (byte)((data[index/2] & 0x0F) | (b << 4)); else data[index/2] = (byte)((data[index/2] & 0xF) | (b & 0x0F)); }