C++ class to Blueprint

Development Programming & Scripting Blueprint
, , ,
1

After working on my blueprint project for a couple weeks, I added a C++ class for a feature that would probably be simpler to make in code than in blueprints (a virtual dice roller).
At first I tried to make a C++ class based on the blueprint that would use it. My BP didn’t show up in the All Classes list so I just added it as an actor.
I added my class in as an actor and saved it to the default source folder. Two of the class’s five UFUNCTIONs are BlueprintCallable since they are the only ones that would be used in the BP. I closed out the editor when my class was done and rebuilt both the project and the engine just to be safe.
I the ran the editor from Visual Studio (with build config set to Development Editor) and tried to reparent my BP to the C++ class but the class didn’t appear in the list of availale classes. I then tried to create a Blueprint based off of the C++ class but, once again, it didn’t appear in the list.

This is my first time trying to cross C++ and Blueprints so I’m not sure how the process works.

UPDATE: I’ve got a new problem now: whenever I try to build the project or run the code, I get these errors in the header:

cannot open "ProjectName.generated.h" - I thought this file was auto-generated?

expected an identifier - I got this on the line containing GENERATED_BODY()

Function parameter list: Missing ']' - That line contains the following function declaration: int32 Max(int32 list[], int32 size, int32& index);. No idea what this means.

I wasn’t getting these errors before but I’m getting them now. I tried getting rid of the UCLASS() parameters and it still happens.

2

did you put your UFUNCTION to public. by default everything is private, if private u can only access from the class, if public u can access from casting

3

Use the following:

UFUNCTION(BlueprintCallable, Category=CPP_Function_In_Blueprint) <YOUR FUNCTION DEFINITION HERE>

The BlueprintCallable parameter in the UFUNCTION() macro is important.

4

Yes, my UFUNCTIONS are all public.

5

I’ve got that on the ones I want to use in the BP.

6

Oh didn’t read through your question carefully ^^
Make sure you class is inherit from the same class as your BP, like you cannot reparent APawn BP to Actor inherit class. If your class is from UObject and u want to use in blueprint u need to add this UCLASS(BlueprintType, Blueprintable)

7

Try:

UFUNCTION(BlueprintImplementableEvent, Category=CPP_Function_In_Blueprint) <YOUR FUNCTION DEFINITION HERE>

Whenever your C++ function is called, it sends out an event. In your blueprint, you use that event to do whatever you want.

8

Ok, I created a new project and the main problem is solved now. I’m still getting the ‘Function parameter list’ thing, so I’ll post a new question for that.