GameObject buf = Instantiate(crystal);
            float x = Random.Range(-radius, radius);
            float z = Random.Range(-radius, radius);
            buf.transform.position = transform.position + new Vector3(x, 0, z);
            float y = terrain.SampleHeight(buf.transform.position);
            buf.transform.position = new Vector3(buf.transform.position.x, y, buf.transform.position.z);