UAnimInstance::GetStateMachineInstance

function Engine Since 4.0

#include "Animation/AnimInstance.h"

Access: public Specifiers: const

Description

Retrieves the runtime state machine node instance by its index. Use this to query the current state, active transitions, state weights, and other runtime information about a state machine defined in the Animation Blueprint.

Caveats & Gotchas

• Returns nullptr if MachineIndex is INDEX_NONE or out of range. Always validate the index (typically obtained from GetStateMachineIndex) before calling this.
• The returned pointer is const — state machine state cannot be modified directly through this accessor. To influence state machine behavior, set anim instance variables that drive transition rules or use transition events.

Signature

const FAnimNode_StateMachine* GetStateMachineInstance(int32 MachineIndex) const

Parameters

Name	Type	Description	Default
MachineIndex	int32	The index of the state machine, obtained from GetStateMachineIndex or GetStateMachineIndexAndDescription.	—

Return Type

const FAnimNode_StateMachine*

Example

Query state machine runtime state C++

bool UMyAnimInstance::IsInLocomotionState(FName StateName) const
{
    int32 MachineIndex = GetStateMachineIndex(FName("Locomotion"));
    if (const FAnimNode_StateMachine* SM = GetStateMachineInstance(MachineIndex))
    {
        int32 StateIndex = SM->GetCurrentState();
        // Compare against expected state
        IAnimClassInterface* AnimClass = IAnimClassInterface::GetFromClass(GetClass());
        if (const FBakedAnimationStateMachine* Desc = GetMachineDescription(AnimClass, const_cast<FAnimNode_StateMachine*>(SM)))
        {
            return Desc->States.IsValidIndex(StateIndex) &&
                   Desc->States[StateIndex].StateName == StateName;
        }
    }
    return false;
}

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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