Scene Overlay vs Visibility Actuator

Game Engine Game Engine Support and Discussion
1

Hi guys,

Was hoping the community can clarify something for me.

What is the difference between using a scene overlay and a visibility actuator to display something on your game?

What I mean is say, for example, you have it so whenever the player presses P, a box appears and allows them to drop what is in the left hand, right hand, or both hands depending on which key they press next. Example of what I mean:

overlayvsvisible.png1347×399 9.6 KB

So I know how to do this with both a scene overlay with the box, as well as just a plane in the same scene that has a visibility actuator turned off and is parented to the camera. Which method is better/why? Or does it not matter at all, maybe we could assume that there would be many boxes of a similar nature if that would effect the answer.

Thanks
-KB

2

Although overlay and visibility are similar, they both are used for different applications.
What you are looking for is the overlay scene, as that would be most effective in your intentions.
why?
An overlay scene is usually for HUD (Heads Up Display), which is “parented” in a way to your camera. this HUD will typically hold bullets, GUI, mag amount, direction of shot on impact, and other things. Overlay scenes can also be used for in-game menus, where the player is not totally out of the game once the menu is activated. Apart from that, Overlays can also be used for minimaps and storage of stuff.

Visibility, on the other hand, is directly tied to the game. Maybe you don’t want a player to be able to see something, but have that object’s actions still impact the game; for example, an invisible player in a multiplayer game. The HUDs created with a visibility actuator will not be as effective, because you will have to attach/message the object each and every time it is called, where in an overlay you just need to use the actuator.

Hope this helps :slight_smile:

3

Overlay scene:

  • always at the same relatve position of the screen ( unless you explicitly change that)
  • very easy to manage
  • no influence from the background scenes (e.g. Lamps)
  • no inteaction with level objects (e.g. Intersecting walls)
  • keeps the players status display separate
  • can easily be replaced
  • simple to be reused with other levels/scenes
  • very simple to hide/show
  • can run own animations without effecting the background scene (scrolling, transition effects etc.)
  • no accidential side effects when seeing the background scene from onother camera.
  • you can suspend the background scenes if necessary
  • you can have multiple overlay scenes at the same time (menu, hud, pause etc.)
4

Okay, thank you for clarification guys!