How to use editor classes from within an actor class

Development Programming & Scripting
1

I’ve added the following to the top of my HelloWorldPrinter.h file (which was created from this programming starter documentation project). The goal is to auto create a new cube from code within the editor as a proof of concept.

#include "UnrealEd.h"

I then have the following in my .cpp, which intellisense seems to agree with just fine. Which was borrowed from Unreal’s own test code in the repo.

UWorld* World = GEditor->LevelViewportClients[0]->GetWorld();
UCubeBuilder* cubeBuilder = Cast<UCubeBuilder>(GEditor->FindBrushBuilder(UCubeBuilder::StaticClass()));
cubeBuilder->X = 4096.0f;
cubeBuilder->Y = 4096.0f;
cubeBuilder->Z = 128.0f;
cubeBuilder->Build(World);
GEditor->Exec(World, TEXT("BRUSH MOVETO X=0 Y=0 Z=0"));
GEditor->Exec(World, TEXT("BRUSH ADD"));

However, when I go to build I get the following error (yadayada = the long path to my project).

yadayada.....lib and object yadayada.exp

HelloWorldPrinter.cpp.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) private: static class UClass * __cdecl UCubeBuilder::GetPrivateStaticClass(wchar_t const *)" (__imp_?GetPrivateStaticClass@UCubeBuilder@@CAPEAVUClass@@PEB_W@Z) referenced in function "class UCubeBuilder * __cdecl Cast<class UCubeBuilder>(class UObject *)" (??$Cast@VUCubeBuilder@@@@YAPEAVUCubeBuilder@@PEAVUObject@@@Z)

HelloWorldPrinter.cpp.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: class UBrushBuilder * __cdecl UEditorEngine::FindBrushBuilder(class UClass *)" (__imp_?FindBrushBuilder@UEditorEngine@@QEAAPEAVUBrushBuilder@@PEAVUClass@@@Z) referenced in function "public: virtual void __cdecl AHelloWorldPrinter::BeginPlay(void)" (?BeginPlay@AHelloWorldPrinter@@UEAAXXZ)

HelloWorldPrinter.cpp.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) class UEditorEngine * GEditor" (__imp_?GEditor@@3PEAVUEditorEngine@@EA)

yadayada.dll : fatal error LNK1120: 3 unresolved externals

Is there a better way to include the editor classes and have them resolved? Or am I doing something wrong.

2

Are you linking to the UnrealEd module?

1 Like
3

Probably not, how do I do that?

4

In the .Build.cs file for whatever you’re working on, they’ll be a list of PrivateDependencyModuleNames and you’ll likely just need to add “UnrealEd” to that list (alternatively it may need to go into PublicDependencyModuleNames depending on where/how you’re using it).

For more information on UBT module dependencies, see: What is the difference between PublicDependencyModuleNames and PrivateDependencyModuleNames - Plugins - Epic Developer Community Forums

I’m curious about how you managed to include UnrealEd.h without that though, so perhaps you already have it.

1 Like
5

That worked! I was messing with build.cs at one point, but it wasn’t in there just now, so maybe something got cached.

1 Like
6

hello,Can you give me a complete code?

7

So, this fixes the compilation error building the editor, but then if you add UnrealEd to your build.cs file you get errors when compiling non-editor builds like “Development”. is there another solution?

8

Can’t use editor code outside editor builds. Best not to rely on that code during runtime. You can use

#if WITH_EDITOR

#endif // WITH_EDITOR

to wrap your editor only code so it doesn’t try to compile, but if you gotta have it for your concept/feature/game to work, then best to move on to your own solution or to a different concept/feature/game.