Line trace: detect object Within the viewport

[TakeTimeGames]

@Inph1del;695796

is this just in general or do you have specific things you want to know are in view port?

Example if your looking for a bool is such and such in view port that I don’t know about but you can track a few objects. Keep in mind this requires tracking a objects location every frame.

So if you have kb object no big deal it’s basically like a radar…

You can dot prod the actor location to your forward vector and find the angle is positive. And also check if length is in range this does mean you see it through walls of course. And additional line trace if that is true would need to be done to know if it’s actually visable.

But it’s only heavy on computation if your trying to get a ton of actors information.

Explain more and I’ll try and see if I have a solution.

@OptimisticMonkey;695810

You need to check whether the actor is in the camera view frustum.

You can do this manually against the frustum planes.

Another approach is to leverage last render time:
https://docs.unrealengine.com/latest/INT/BlueprintAPI/Rendering/WasRecentlyRendered/index.html

This approach might work for you if there is a single actor e.g. Slenderman that you are concerned about.

Here is an old discussion on it:
How to figure out if something can be seen by the player in BP? - Programming & Scripting - Epic Developer Community Forums

Back , after i find my answer , first thanks for your replay , second see video in below , i managed to make detect enemy in view port

Unreal Engine Demo 04 17 2017 00 44 02 08

Now this is really what i want to make it , i want when player see enemy , the enemy will be dissolve or like fade out , but the problem can not access other blueprint
is anyone know how to make this work ? i tried by cast to and new variable , too bad ???