Camera trigger events question(s)

Camera Bounds event trigger and hidden object blueprint questions

I am seeking advice or direction as there are two very specific things I would like to do or express through blueprints and not sure where to even start.

The first, I’d like to designate an area. Maybe an invisible box or rectangle Idk. And if this box is viewed on a certain axis it will hide an actor. Or actors with in its space. Or invert the view of the scene outside the box. Ideally this objects would still be loaded and accessible, just not visible from the one side of the box.

The second, I’d like to designate an area. Again probably a box. And If the players camera is looking at the area without any obstruction from another mesh and the player is with x units of the area then trigger event. I’d rather avoid this be an event trigger based on players location alone or location based trigger as I want to do something out of view of the player

Hey @Dowslain!

For your first task, a few questions:

  • Will this area be accessible from the point you are looking from (aka can you walk into it?)
  • Do you still need collision on those actors?

For your second task, what you can do is do a Line Trace or a Multi Line Trace that requires a specific distance to activate using something like the Get Distance To node. Here is a great non-Epic affiliated video explaining more about that node:

Any additional specifics or information you can provide may go a long way in solving your problem!

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Thank you for the response!

For the first task i outlined above.
Yes and no? Honestly looking at it i should have broken that one into two questions.

My goal with the scene is to have a door into a room, then create the rectangle around it to hide rooms flagged meshes as to only have it visible as looking through the opened door.
Essentually making the appearance of a door in space opening to a larger space.
But aside from passing through the door into the room via the door i didnt intend to make the rectangle or square or whatever that im using to hide the room be interactable to the player or have a collision.

For the second part of that first question the “or invert view” my idea with how that part of the scene worked at least my head was that upon entering the room the player would go down a hall and look out a broken section of the wall to have the view upside down. With the skybox appearing below and the rest of the scene appearing in the sky. But like previously for that instance i wouldnt need collision and it wouldnt be accessible to the player outside of viewing it.

For the second question, im glad i was on the right track! Ty for the video link. Ive been researching this since i posted. Last night i ended up just searching “trigger events ue” until i spiralled into line tracing and bookmarked a few videos to look at today :slightly_smiling_face:

Trying to figure out how to do this basically.

Actually this one might be a better example. Ive read a couple people on different forum posts asking the same question. One person mentions aping the effect with a 2dtexture node? But none of the threads are marked as resolved

Regarding hidden objects in a level.
A disolve area volume like this. Just with something to say everything on a designated axis behind it as viewed from the camera.

Heyy @Dowslain!

I can definitely see what you are doing here. I think what you may want to use instead in this case (especially if you want to eventually make rooms bigger on the inside) is a bit of smoke and mirrors.

I suggest making dummy rooms, or even have your designated room in a different location, and use render targets and possibly smooth transition portals to achieve your effects. Your dummy room will not have any objects you do not want to show, so that way when your players look at the render it does not show up

There are definitely some Marketplace items that can achieve this, and here are some great non-Epic affiliated resources on how to achieve this:

I hope the above contains the solution you need.

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