public override int GetHeightAt(int px, int py)
{
int X = px / ChunkX;
int Y = py / ChunkZ;
int x = px - ((px >> 4) * ChunkX); //(px >> 4) & 0xf;
int y = py - ((py >> 4) * ChunkZ); //(py >> 4) & 0xf;
Chunk c = GetChunk(X, Y);
return c.HeightMap[x, y];
}