Adding Engine Code to your Project

In the FAQ, there’s the following section:

Can I copy and paste the Unreal Engine
code into my own project or engine?

If you use any Unreal Engine code in
your product (even just a little),
then your entire product is governed
by the EULA, and royalties are due.

What does this exactly mean?

Especially the part entire product is governed by the EULA concerns me.

  1. Is this some kond of Copy Left? If I copy a line from the unreal engine to my project, I give up all rights for my project?
  2. Or is this more of the kind “If you copy a line of our engine, you are using our engine.”

Option 2 is something, I could live with :slight_smile:

I am working on a project using the Unreal Engine. I have a function, I would like to copy from the engine source to my own project and modify a little.

  • The royalities are due anyway, as I am using the Unreal Engine for this project. So no change here for my project here?
  • Of course I wouldn’t be allowed to publish the part of the code, I’ve copied into my project

Is there anything else changing for my project, if I would copy the function into my project?

Thanks for the Answer :slight_smile:
I hope one of the Unreal Staff will confirm this, so we both can be 100% sure :wink:

I want to take the FConfigFile::ProcessInputFileContents function and use it as a general ini parser maintaining the order of the ini file properties, for other purposes than configuration files

I’m not 100% sure here, but it means that if you copy function to your own project unrelated to UE4, that project will be effected by UE4 EULA and you need to pay royalties. But if you make normal Unreal Engine project, you are under UE4 EULA either way, so it really does not make difference. In other words, whatever you use UE4 in project in anyway, that project becomes officially UE4 project and is effected by UE4 EULA.

Btw what function you want to modify and how?

is correct - it means if you use even only one line of the engine in your product, it’s covered by the EULA and royalties may be owed. But you always own the parts of your product that aren’t UE4.

Thanks for the Answer :slight_smile: