UAnimInstance::GetInstanceMachineWeight

function Engine Blueprint Since 4.8

#include "Animation/AnimInstance.h"

Access: public Specifiers: UFUNCTION

Description

Returns the current blend weight (0.0–1.0) of the state machine at the given index. Used internally by generated Animation Blueprint code to expose state machine weights to transition rules and blend logic.

Caveats & Gotchas

• MachineIndex is assigned by the AnimBP compiler and can change whenever the animation blueprint is recompiled or the state machine graph is restructured. Never hard-code a machine index in C++ — retrieve it via GetStateMachineIndex() or use the generated blueprint functions.
• This function is marked BlueprintInternalUseOnly; it is intended to be called from auto-generated AnimBP code, not from hand-authored Blueprint graphs. Calling it directly in C++ is valid but the index must be obtained from the compiled AnimBP's internal constants.

Signature

UFUNCTION(BlueprintPure, Category="Animation", meta=(BlueprintInternalUseOnly = "true"))
float GetInstanceMachineWeight(int32 MachineIndex) const;

Parameters

Name	Type	Description	Default
MachineIndex	int32	Index of the state machine node within the compiled animation blueprint.	—

Return Type

float

Example

Read machine weight from a compiled AnimBP constant C++

// MachineIndex comes from the AnimBP compiler — access via GetStateMachineIndex
int32 MachineIdx = GetStateMachineIndex(FName("LocomotionSM"));
if (MachineIdx != INDEX_NONE)
{
	float Weight = GetInstanceMachineWeight(MachineIdx);
	UE_LOG(LogAnim, Log, TEXT("LocomotionSM weight: %f"), Weight);
}

Version History

Introduced in: 4.8

Version	Status	Notes
5.6	stable	—

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