if (Input.GetMouseButtonDown(0)) {
            RaycastHit hit;
            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);

            if (Physics.Raycast(ray, out hit, rayLength, lm)) {
                hit.transform.GetComponent<MeshRenderer>().material = material;
                GameObject go=Instantiate(build, hit.transform);
                go.transform.localScale=new Vector3(5,5,5);
            }
        }