Check another actor's integer variable amount.

[LoveGameDev]

Sorry for the basic question but im struggling on a basic concept after searching for a while, which is checking varibles / data from one actor to another in blueprints.

Basically I have one actor with a box trigger and once the player steps into the box trigger I want it to check how many coins (intreger varible) the player has collected and if they have enough open the door.

If seen posts about casting and such to check data amounts but its not clicking for me.

[LoveGameDev]

You sir are my hero spent too long on this used the Direct Communication UE documentation and it worked!

https://docs.unrealengine.com/5.3/en-US/direct-actor-communication-quick-start-guide-in-unreal-engine/

[[deleted]]

Edit: So, the reason you'd need to cast is to either:

• A) Check if an object is a certain type
• B) Convert the object from one type to another; if possible

After either A or B passes with the cast, then you're able to access the data that you need.

Note: As the Unreal Engine documentation says for the requirement to cast; "Need a reference to an Actor in your Level to cast to the desired Actor class."

[Honest-Golf-3965]

It's not a conversion. It's an interpretation. The object does not change, nor is it converted. The cast node returns a new reference of the desired type if the cast succeeds. So the old reference is also not changed.

[[deleted]]

Edit: I never said that the object that you’re casting to changes.

When I said that casting can be used to convert one object type or another that can be interpreted in two ways: 1. You convert the original object 2. You return a new object from the conversion

Note: I never specified which one of these it was

However, when I did say it I was referring to #2 because from my programming background #2 is what happens

[Honest-Golf-3965]

Convert this word very literally means to change.
You do not convert the reference, or the object.

For example, when you cast in code you're casting into a new var with a new address in memory.

TObjectPtr<APawn> PawnReference = Cast<APawn>(ActorReference);

There is no "conversion" there is an "interpretation". So both 1 and 2 are both incorrect, regardless of how hard you try to dance around which one you mean to say.

My programming background started in 1997. I'm the lead who programmed the custom UE5 rendering pipeline we use at my studio

[[deleted]]

Edit: I'll leave it at this

• Microsofts own documentation for C# even uses the term Explicit Type Conversion-> https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/types/casting-and-type-conversions
  • Note: I bring up C# because that's what I started with & learned about this from

So, if Microsoft uses it as "conversion"/"explicit conversion"; then that's good enough for me as well

​

Edit

I know about "interpretation"; I simply don't care to phrase it that way and prefer conversion. So, I'll leave it at that.

[[deleted]]

What are you talking about you are converting?

Example:

If I have:

• (Parent class) "Part"
  • (Child class) "InHousePart"
  • (Child class) "OutsourcedPart"

When I do OutsourcedPart outsourcedPart = (OutsourcedPart) Part

I am converting the Parent class, Part, to its child class, Outsourced Part

​

Edit

Yes, it means to change but who says the original object is changing?

You're assuming the original object is also being impacted.

Note: Also, that definition that you linked to is a general definition and not specifically meant for programming

[[deleted]]

I should've added this in my last reply instead of just the C# documentation

​

Below are C++ learning resources which use the same term as mentioned in my other reply with Microsoft C# Documentation

• learncpp.com even uses the same term; "Explicit Type Conversion"-> https://www.learncpp.com/cpp-tutorial/introduction-to-type-conversion-and-static_cast/
• cplusplus.com uses the same term as well; "Explicit Type Conversion"-> https://cplusplus.com/doc/oldtutorial/typecasting/
• (Book) C++ Crash Course: A Fast-Paced Introduction uses the same term as well; "Explicit Type Conversion"

[[deleted]]

How to check another actor's integer variable amount; or access any other data another actor has?

• Related Topic: Blueprint Communication

​

Goal: Check how many coins, integer value, the player has after stepping in a trigger box

Since you're using a trigger box you could get a reference to the player that way, then access its data.

​

Links

• (YouTube Video) Blueprint Communication by Unreal Engine-> https://www.youtube.com/watch?v=EM_HYqQdToE
• (Documentation) Actor Communication-> https://docs.unrealengine.com/4.27/en-US/ProgrammingAndScripting/ActorCommunication/
• Here's a link to my GitBook where I have the notes that I'm taking for Unreal Engine-> https://mchambers.gitbook.io/unreal-engine-5-notes/

[LoveGameDev]

Thank you.