void Update()
{
//find out what are you clicking on by firing a ray from it
if(Input.GetMouseButtonDown(0))
{
RaycastHit hit = new RaycastHit();
ray=Camera.main.ScreenPointToRay(Input);
if (Physics.Raycast(ray, out hit)){
if(hit.collider.tag==“paper”){
texture=hit.collider.gameObject;
//before enabling you should convert game object to texture
texture.enable=true;
}
}