How to find the corresponding C++ API of a Blueprint API?

Development Programming & Scripting
1

I’m just checking here, but when you have Visual Studio installed, you can just double click on the BP node?

2

Hi everyone.

I’m just starting to playing UE4 these days. During my learning, I found one of my biggest problem is that some times I google for some questions and got some answers with Blueprints, but what I actually want to know is how to do the same job with C++, and I have no idea about how can I get to the document of a C++ equivalent way from the Blueprint API document.

For example, I search for ‘Project World to Screen’, then I can easily got this document page about the utility node which do this job, but on this page I can not find any direction on where the C++ version of this API is, what header should I include, what function should I call.

I know I can use editor to convert Blueprint to C++, it can help me figure out some C++ version APIs somehow, but I’m still wishing for a proper way to find it, which should be not that ‘dirty’.

So is there any chance to solve this problem? Or at least improve my effectiveness on searching C++ documents (including which header should be included) rather than rush into Blueprints? Thanks for any help.

3

Thanks for your comment, but I really don’t want to create a BP at all…but…guess I have to change my mind if this is really that difficult…

4

In Visual Studio you can press Ctrl+, or Ctrl+T to search for symbols or filenames.

Most of the time, blueprint nodes call an underlying C++ function of the same name. So press Ctrl+T and type the name of the node without spaces (eg. “ProjectWorldToScreen”) and you should find results very quickly.

If you are out of luck and get no result, that means the node was given a different name via the UFunction meta DisplayName="…". In that case you can launch a full search (Ctrl+Shift+F) for the node name and you should find it.

If you already have editor open, another solution is to copy the node and paste it in text editor. There you can easily find information about the function reference :

Begin Object Class=/Script/BlueprintGraph.K2Node_CallFunction Name="K2Node_CallFunction_2"
   ...
   FunctionReference=(MemberParent=Class'"/Script/Engine.GameplayStatics"',MemberName="ProjectWorldToScreen")
1 Like
5

Thank you very much. Guess that’s it.

6

The quickest way I’ve found is to copy the Blueprint node and paste it into a text editor.

For example here’s a node I copied:

Begin Object Class=/Script/BlueprintGraph.K2Node_CallFunction Name="K2Node_CallFunction_11" ExportPath="/Script/BlueprintGraph.K2Node_CallFunction'/IslandGenerator/Spawner/BP_Spawner.BP_Spawner:EventGraph.K2Node_CallFunction_11'"
   bIsPureFunc=True
   FunctionReference=(MemberParent="/Script/CoreUObject.Class'/Script/NavigationSystem.NavigationSystemV1'",MemberName="GetNavigationSystem")
 ....
End Object

I omitted some of the output, but what you’re looking for is the line starting with “FunctionReference” which will point you to the C++ class and method in this case NavigationSystemV1::GetNavigationSystem.