Creating a GUI button above 2D gameobject

Questions & Answers
1

Hi I’m making a 2D game where the player has to move between the cities.
I created a ‘city’ prefab and added multiple city gameobject in the scene.

when the player click on a city that is next to the current city, a button has to pop up above the city that the player clicked and if u click on the button, the player moves to that city.

I used OnGUI to create the button that pops up.
However, the GUI button is being created on the top left corner instead of above the city gameobject.
How do I make the button to pop up above the gameobject?

*I am using orthographic camera projection

this is my script for OnGUI function

	void OnGUI () {

		if (selected) {
			if (GUI.Button (new Rect (selectedCity.transform.position.x, selectedCity.transform.position.y + 10, 100, 40), "Go to this city")) {
 				selected = false;
			}
		}
	}
2

GUI methods use screen positions (pixels, but your selectedCity.transform.position returns units). Use Camera.WorldToScreenPoint to calculate selected city screen position.

void OnGUI () {
     if (selected) {
         var screenPosition = Camera.main.WorldToScreenPoint(selectedCity.transform.position);
         if (GUI.Button (new Rect (screenPosition.x, screenPosition.y + 10, 100, 40), "Go to this city")) {
              selected = false;
         }
     }
 }

Look at the docs