br>  let target_plane_pos = world.planes[target_plane_index];<br>  let missile = world.planes[plane_index].missiles[missile_index];<br>  missile.position = missile.position.towards(target_plane_pos);<br>}<br><br>Blackbeard: &amp;quot;Indeed! But notice how we&amp;#39;re passing the entire World in. Because structs can&amp;#39;t refer to each other by index, we often have to pass the entire world as a parameter, making the world effectively global. Not great for encapsulation.&amp;quot;<br><br>Redbeard: &amp