void Update()
    {
        if (Input.GetMouseButton(0))
        {
            ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            if (Physics.Raycast(ray, out hitInfo))
            {
                snow = hitInfo.collider.gameObject.GetComponent <DeformableMesh>();

                if (snow)
                {
                    Vector3 inputPosition = hitInfo.point;
                    inputPosition += hitInfo.normal * 0.1f;
                    snow.AddForce(inputPosition);
                }
            }
        }
    }