Game/GigLine/Source/GigLine/GigLineVehicle.cpp

@@ -265,8 +265,27 @@ void AGigLineVehicle::BeginPlay()
 
 void AGigLineVehicle::Tick(float DeltaSeconds)
 {
+	// Which writer moves the actor? Sample the transform before and after the base class tick:
+	// a change between the two happened inside APawn::Tick (movement component, attachment
+	// update, animation), a change between this frame's exit and the next frame's entry came
+	// from somewhere else entirely.
+	const FVector BeforeSuper = GetActorLocation();
+
 	Super::Tick(DeltaSeconds);
 
+	const FVector AfterSuper = GetActorLocation();
+	if (!AfterSuper.Equals(BeforeSuper, 1.0))
+	{
+		static float LoggedThisPhase = -1.0f;
+		if (SettleElapsed - LoggedThisPhase > 0.25f)
+		{
+			LoggedThisPhase = SettleElapsed;
+			UE_LOG(LogTemp, Warning,
+				TEXT("GigLine vehicle writer: inside Super::Tick %.0f -> %.0f (dz %.0f)"),
+				BeforeSuper.Z, AfterSuper.Z, AfterSuper.Z - BeforeSuper.Z);
+		}
+	}
+
 	// One settled-state report: proves the physics body exists, is simulating, and has
 	// come to rest on the road rather than falling through it. Everything else about the
 	// driving behaviour is measured later; this is the "is it real" check.