Custom BlendSpace Node: Why is there a compilation error when I expose the BlendSpace pin?

Development Programming & Scripting
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1

I’m working on a custom BlendSpace node that is a child of the FAnimNode_BlendSpacePlayer class. The functionality is there…until I expose the BlendSpace pin as a variable. Then my Blueprint won’t compile. The below video describes the issue.

The error seems to be rooted in the ValidateAnimNodeDuringCompilation function of the AnimGraphNode class for my node. The function is the following:

void UAnimGraphNode_BlendSpaceDMEvaluator::ValidateAnimNodeDuringCompilation(USkeleton* ForSkeleton,
	FCompilerResultsLog& MessageLog)
{
	Super::ValidateAnimNodeDuringCompilation(ForSkeleton, MessageLog);
	
	ValidateAnimNodeDuringCompilationHelper(ForSkeleton, MessageLog, Node.GetBlendSpace(),
		UBlendSpace::StaticClass(), FindPin(GET_MEMBER_NAME_STRING_CHECKED(FAnimNode_BlendSpaceDMEvaluator,
			GetBlendSpace())), GET_MEMBER_NAME_CHECKED(FAnimNode_BlendSpaceDMEvaluator, GetBlendSpace()));
}

After printing to the log, I see that GetBlendSpace() returns a nullptr, which doesn’t make sense (to me), since GetBlendSpace() is a public function inherited from my node’s parent class that returns the parent class’s BlendSpace private member variable — the same BlendSpace member variable accessible in a standard BlendSpace Player.

Can anyone point me in the right direction?

3

To those who may search through the forums later, I think I solved my problem.

I had to change the parent class of my node to FAnimNode_BlendSpacePlayerBase and create my own BlendSpace variable in my reparented class. This, of course, required a lot of tedious function create. However, to the best of my knowledge, this approach was required because of the GET_MEMBER_NAME_STRING_CHECKED macro within the ValidateAnimNodeDuringCompilationHelper function (of the AnimGraphNode class), which checks the Class for the ClassVariable, as in: GET_MEMBER_NAME_STRING_CHECKED(Class, ClassVariable). If ClassVariable is not in the Class, the macro returns NULL. When I originally had my class parented to the FAnimNode_BlendSpacePlayer class, the BlendSpace variable was in that class rather than my child class, which caused the issue. After reparenting, the BlendSpace variable is now in my custom (child) class.