Why does Anim BP warn about fast path with simple property access?

Fast path requires direct field read with no virtual or function dispatch. Mark UPROPERTY(BlueprintReadOnly) public; remove BlueprintGetter; avoid traversing pointer chains.

Animation graph evaluates on worker thread. Fast path = direct memory read, no thunks. Slow path = call game thread via TaskGraph; thread-safety overhead.

For functions called from anim graph: mark [BlueprintThreadSafe] in C++. Tells Unreal it's safe to call on worker; may bypass safe path penalty.

Fix: Anim BP Property Access Fastpath Warning

Quick answer: Property must be UPROPERTY(BlueprintReadOnly) public; no BlueprintGetter; no pointer chain.

Anim BP shows yellow warning: not on fast path. Reading Character.GetVelocity().Size2D() chains accessors and a function call.

The Fix

// AnimInstance subclass
UPROPERTY(BlueprintReadOnly, Category="Animation")
float Speed = 0.f;

UPROPERTY(BlueprintReadOnly)
bool bIsFalling = false;

virtual void NativeUpdateAnimation(float Dt) override {
    Super::NativeUpdateAnimation(Dt);
    auto* C = TryGetPawnOwner();
    if (!C) return;
    Speed = C->GetVelocity().Size2D();
    bIsFalling = C->GetCharacterMovement()->IsFalling();
}

NativeUpdateAnimation runs on game thread; reads game state. AnimGraph reads cached members on fast path.

Verifying

Yellow warning gone. AnimGraph compile log shows fast-path success.

“Cache. Read direct. Fastpath.”

Related Issues

For Property Access threading, see threading. For cached pose, see cached pose.

Direct fields. Fastpath.