Render the object

How do I turn on/off the render of a object

like the object collide with water then turn the render on …

The easiest way is to use the renderer.enabled

renderer.enabled = true;

If you turn on all the renderers of any object that hits this object perhaps something like this would work for you…

void OnCollisionEnter (Collision collisionInfo)
{
    foreach(Renderer r in collisionInfo.gameObject.GetComponentsInChildren(typeof(Renderer)))
   {
      r.enabled = true;
   }
}

Thanks, that’s what I was looking for