When using FTimeline::GetAllCurves, I get an error: "error LNK2019: unresolved external symbol"

Development Programming & Scripting
1

When using FTimeline::GetAllCurves, I get an error: “error LNK2019: unresolved external symbol”.

I am creating a custom AnimInstance.

I have inluded in my header file: “#include “Runtime/Engine/Classes/Components/TimelineComponent.h””

I have tried calling it as:

TSet<class UCurveBase*> inOutCurves;
FacialTimelines[0].FTimeline::GetAllCurves(inOutCurves);

as well as:

TSet<class UCurveBase*> inOutCurves;
FacialTimelines[0].GetAllCurves(inOutCurves);

My timeline array is declared in my header file as:

UPROPERTY(BlueprintReadWrite, Category = "FalParserAnimInstance")
TArray<FTimeline> FacialTimelines;

Full Dump:

1>------ Build started: Project: MikuCode, Configuration: Debug_Editor x64 ------
1>  Deleting junk file: "..\..\Engine\Binaries\Win64\HTML5\UE4Editor-HTML5TargetPlatform-Win64-Debug.dll".
1>  Deleting junk file: "..\..\Engine\Binaries\Win64\HTML5\UE4Editor-HTML5TargetPlatform-Win64-Debug.pdb".
1>  Building UnrealHeaderTool...
1>  Target is up to date.
1>  Parsing headers for MikuCodeEditor
1>  Reflection code generation finished for MikuCodeEditor and took 3.949
1>  Performing 3 actions (max 4 parallel jobs)
1>  [2/3] link.exe UE4Editor-HTML5TargetPlatform-Win64-Debug.dll
1>  FalParserAnimInstance.cpp
1>     Creating library Y:\UESource\UnrealEngine\Engine\Intermediate\Build\Win64\UE4Editor\Debug\UE4Editor-HTML5TargetPlatform-Win64-Debug.lib and object Y:\UESource\UnrealEngine\Engine\Intermediate\Build\Win64\UE4Editor\Debug\UE4Editor-HTML5TargetPlatform-Win64-Debug.exp
1>  [3/3] link.exe UE4Editor-MikuCode-Win64-Debug.dll
1>     Creating library Y:\MMD\Unreal Engine\UnrealProjects\MikuCode\Intermediate\Build\Win64\MikuCodeEditor\Debug\UE4Editor-MikuCode-Win64-Debug.lib and object Y:\MMD\Unreal Engine\UnrealProjects\MikuCode\Intermediate\Build\Win64\MikuCodeEditor\Debug\UE4Editor-MikuCode-Win64-Debug.exp
1>FalParserAnimInstance.cpp.obj : error LNK2019: unresolved external symbol "public: void __cdecl FTimeline::GetAllCurves(class TSet<class UCurveBase *,struct DefaultKeyFuncs<class UCurveBase *,0>,class FDefaultSetAllocator> &)const " (?GetAllCurves@FTimeline@@QEBAXAEAV?$TSet@PEAVUCurveBase@@U?$DefaultKeyFuncs@PEAVUCurveBase@@$0A@@@VFDefaultSetAllocator@@@@@Z) referenced in function "public: void __cdecl UFalParserAnimInstance::OnTimelineEventTick(void)" (?OnTimelineEventTick@UFalParserAnimInstance@@QEAAXXZ)
1>Y:\MMD\Unreal Engine\UnrealProjects\MikuCode\Binaries\Win64\UE4Editor-MikuCode-Win64-Debug.dll : fatal error LNK1120: 1 unresolved externals
1>  -------- End Detailed Actions Stats -----------------------------------------------------------
1>ERROR : UBT error : Failed to produce item: Y:\MMD\Unreal Engine\UnrealProjects\MikuCode\Binaries\Win64\UE4Editor-MikuCode-Win64-Debug.dll
1>  Cumulative action seconds (8 processors): 0.00 building projects, 1.18 compiling, 0.00 creating app bundles, 0.00 generating debug info, 0.60 linking, 0.00 other
1>  UBT execution time: 17.72 seconds
1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.MakeFile.Targets(38,5): error MSB3073: The command "Y:\UESource\UnrealEngine\Engine\Build\BatchFiles\Build.bat MikuCodeEditor Win64 Debug "Y:\MMD\Unreal Engine\UnrealProjects\MikuCode\MikuCode.uproject"" exited with code -1.
========== Build: 0 succeeded, 1 failed, 1 up-to-date, 0 skipped ==========
2

For clarification, I would like to know how to properly get the curves out of FacialTimelines, without getting the external error.

I do not understand why “unresolved external symbol” shows up, as I’m just calling FTimeline’s built in function.

3

Well,
this function isn’t exported from the engine DLL, and You have to add ENGINE_API keyword just like this:

ENGINE_API void GetAllCurves(TSet& InOutCurves) const;

Regards

Pierdek

4

Thank you! Adding the ENGINE_API keyword worked.