UMjGeneralActuator

Represents a 'general' actuator in MuJoCo.

Attribute	Value
Kind	Class
UE Macro	UCLASS
Inherits	UMjActuator
Blueprint Spawnable	✅ Yes

Properties Functions

Properties

Public Properties

Property	Type	Description
Type	EMjActuatorType	The type of actuator dynamics (e.g. Motor, Position).
TransmissionType	EMjActuatorTrnType	The transmission type connecting the actuator to the system.
MjClassName	FString	Optional MuJoCo class name to inherit defaults from.
TargetName	FString	Name of the target element (Joint, Tendon, Site, etc.) this actuator acts upon.
Gear	TArray<float>	Gear ratio scaling for the transmission.
GainPrm	TArray<float>	Custom gain parameters (gainprm).
BiasPrm	TArray<float>	Custom bias parameters (biasprm).
bCtrlLimited	bool	Whether control limiting is enabled.
bForceLimited	bool	Whether force limiting is enabled.
bActLimited	bool	Whether internal activation state is limited.
CrankLength	float	Length range for muscle/tendon actuators.
SliderSite	FString	Name of the slider site for slider-crank transmission.
RefSite	FString	Reference site name.
Group	int	Actuator group ID.
bActEarly	bool	Whether to apply actuation early (before other forces).
DynPrm	TArray<float>	Custom dynamic parameters (dynprm).

Type

The type of actuator dynamics (e.g. Motor, Position).

• Type: EMjActuatorType
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator

TransmissionType

The transmission type connecting the actuator to the system.

• Type: EMjActuatorTrnType
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator

MjClassName

Optional MuJoCo class name to inherit defaults from.

• Type: FString
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator

TargetName

Name of the target element (Joint, Tendon, Site, etc.) this actuator acts upon.

• Type: FString
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator

Gear

Gear ratio scaling for the transmission.

• Type: TArray
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_Gear)

GainPrm

Custom gain parameters (gainprm).

• Type: TArray
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_GainPrm)

BiasPrm

Custom bias parameters (biasprm).

• Type: TArray
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_BiasPrm)

bCtrlLimited

Whether control limiting is enabled.

• Type: bool
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_CtrlLimited)

bForceLimited

Whether force limiting is enabled.

• Type: bool
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_ForceLimited)

bActLimited

Whether internal activation state is limited.

• Type: bool
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_ActLimited)

CrankLength

Length range for muscle/tendon actuators.

• Type: float
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_LengthRange)

SliderSite

Name of the slider site for slider-crank transmission.

• Type: FString
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator

RefSite

Reference site name.

• Type: FString
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator

Group

Actuator group ID.

• Type: int
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_Group)

bActEarly

Whether to apply actuation early (before other forces).

• Type: bool
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_ActEarly)

DynPrm

Custom dynamic parameters (dynprm).

• Type: TArray
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: Mj Actuator
• Notes: Override-enabled (bOverride_DynPrm)

Functions

Public Functions

General

Function	Returns	Description
ImportFromXml()	void	Imports properties and override flags directly from the raw XML node.
ParseSpecifics()	void	Parses subclass-specific properties from the XML node.
ExtractSpecifics()	void	Extracts subclass-specific properties from the MuJoCo spec mechanism.
RegisterToSpec()	void	Registers this actuator to the MuJoCo spec.
Bind()	void	Binds this component to the live MuJoCo simulation.
GetMjName()	FString	Gets the full prefixed name of this actuator as it appears in the compiled MuJoCo model.
ResolveDesiredControl()	float	Resolves the final control value to apply based on the specified source.
SetNetworkControl()	void	Sets the control value from the ZMQ networked stream.

ImportFromXml

Imports properties and override flags directly from the raw XML node.

• Signature: ImportFromXml(const class FXmlNode* Node)

ParseSpecifics

Parses subclass-specific properties from the XML node.

• Signature: ParseSpecifics(const class FXmlNode* Node)

ExtractSpecifics

Extracts subclass-specific properties from the MuJoCo spec mechanism.

• Signature: ExtractSpecifics(const mjsActuator* Actuator)

RegisterToSpec

Registers this actuator to the MuJoCo spec.

• Signature: RegisterToSpec(class FMujocoSpecWrapper& Wrapper, mjsBody* ParentBody)

Bind

Binds this component to the live MuJoCo simulation.

• Signature: Bind(mjModel* Model, mjData* Data, const FString& Prefix)

GetMjName

Gets the full prefixed name of this actuator as it appears in the compiled MuJoCo model.

• Signature: GetMjName()
• Returns: FString

ResolveDesiredControl

Resolves the final control value to apply based on the specified source.

• Signature: ResolveDesiredControl(uint8 Source)
• Returns: float

SetNetworkControl

Sets the control value from the ZMQ networked stream.

• Signature: SetNetworkControl(float Value)

MuJoCo|Runtime

Function	Returns	Description
SetControl()	void	Sets the internal control input (ctrl) for this actuator.
ResetControl()	void	Resets the control input (ctrl) for this actuator to zero.
GetControl()	float	Gets the current resolved control value being applied.
GetForce()	float	Gets the current force generated by this actuator.
GetLength()	float	Gets the current length of the actuator.
GetVelocity()	float	Gets the current velocity of the actuator.
GetControlRange()	FVector2D	Gets the control range [min, max] from the compiled model. Returns ZeroVector if ctrl is not limited.
GetActivation()	float	Gets the current activation state (for stateful actuators like muscle/intvelocity). Returns 0 if stateless.
SetGear()	void	Sets the gear ratio (expert use).
GetGear()	TArray<float>	Gets the gear ratio.

SetControl

Sets the internal control input (ctrl) for this actuator.

• Signature: SetControl(float Value)
• Blueprint: 🔵 Callable

ResetControl

Resets the control input (ctrl) for this actuator to zero.

• Signature: ResetControl()
• Blueprint: 🔵 Callable

GetControl

Gets the current resolved control value being applied.

• Signature: GetControl()
• Blueprint: 🔵 Callable
• Returns: float

GetForce

Gets the current force generated by this actuator.

• Signature: GetForce()
• Blueprint: 🔵 Callable
• Returns: float

GetLength

Gets the current length of the actuator.

• Signature: GetLength()
• Blueprint: 🔵 Callable
• Returns: float

GetVelocity

Gets the current velocity of the actuator.

• Signature: GetVelocity()
• Blueprint: 🔵 Callable
• Returns: float

GetControlRange

Gets the control range [min, max] from the compiled model. Returns ZeroVector if ctrl is not limited.

• Signature: GetControlRange()
• Blueprint: 🔵 Callable
• Returns: FVector2D

GetActivation

Gets the current activation state (for stateful actuators like muscle/intvelocity). Returns 0 if stateless.

• Signature: GetActivation()
• Blueprint: 🔵 Callable
• Returns: float

SetGear

Sets the gear ratio (expert use).

• Signature: SetGear(const TArray<float>& NewGear)
• Blueprint: 🔵 Callable

GetGear

Gets the gear ratio.

• Signature: GetGear()
• Blueprint: 🔵 Callable
• Returns: TArray