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How to edit existing UE4 Blueprints in C++?

Development Discussion C++ Programming
#1

I posted something similar to this on the blueprints forum but realized I may have posted on the wrong forum. Since it involves both blueprints and C++ not sure which is best, but it seems to me that if you know C++ you will likely be comfortable with BP, where if your a BP user you may not know C++, so I thought this may be a better place for it.

I was wondering how you could edit the functions for existing blueprints? For example if I want to edit the Jump function in the basic character controller, how would I go about doing that?

I’m sure there is an easy way, just need some guidance please!

Thanks!

#2

Jump function from ACharacter class is marked as virtual, this means that you can inherit from ACharacter (by creating new class - AModifiedCharacterBase) and override this function:


virtual void Jump() OVERRIDE;

Then, if you create blueprint (BP_CharacterBase) that uses your type (AModifiedCharacterBase) as a base type, you can use your new Jump implementation.


ACharacter
     ^
     |
AModifiedCharacterBase
     ^
     |
BP_CharacterBase

This could help you:
https://docs.unrealengine.com/latest/INT/Programming/QuickStart/3/index.html
https://docs.unrealengine.com/latest/INT/Engine/Blueprints/TechnicalGuide/ExtendingBlueprints/index.html

Cheers!

#3

Thanks for the response!

Question about this…

Would this completely be remaking a new jump function? Because at the moment I’m “mostly” satisfied with the current jump function. My goal is actually that I just want to do some minor tweaks and add some variance to it. Is there a way to retrieve the current function to just add to it? Or is it only possible to create a new one?

Thanks again.

#4

Yes, this would overwrite existing Jump function (http://en.wikipedia.org/wiki/Method_overriding).

You can copy/paste the same code and then make your tweaks or modify base Jump method.

Cheers!

#5

Thanks.

I understand the concept of overriding (used C# for last few years, but my C++ is rusty as I haven’t used it since early 2008). But when you mention you can copy/paste the same code, do you mean the code from the original jump method?

That’s basically what I’m looking for. I’m installing 4.2 source right now and like a ***** I uninstalled the 4.1 source install first, but if I remmeber correctly, when I was searching for the jump function, the jump function in ACharacter only changed a variable, and I couldn’t quite find the exact class or function that contained the actual coding for the jump method.