UMjBody

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

Properties Functions

Properties

Public Properties

Property	Type	Description
bIsQuickConverted	bool	If true, this body was created via Quick Convert, enabling specific logic like pivot correction.
bDrivenByUnreal	bool	If true, this body's transform is driven by the Unreal Actor/Component, enabling One-Way coupling (Unreal -> MuJoCo).
Gravcomp	float	Anti-gravity force applied to the body, in units of body weight.
bOverride_ChildClassName	bool	If true, overrides the MuJoCo default class name inherited from the parent body's childclass attribute.
ChildClassName	FString	Child class name for this body.
SleepPolicy	EMjBodySleepPolicy	Per-body sleep policy (MuJoCo 3.4+). Default lets the global option decide.

bIsQuickConverted

If true, this body was created via Quick Convert, enabling specific logic like pivot correction.

• Type: bool
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo Import

bDrivenByUnreal

If true, this body's transform is driven by the Unreal Actor/Component, enabling One-Way coupling (Unreal -> MuJoCo).

• Type: bool
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo Physics

Gravcomp

Anti-gravity force applied to the body, in units of body weight.

• Type: float
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo Physics
• Notes: Override-enabled (bOverride_Gravcomp)

bOverride_ChildClassName

If true, overrides the MuJoCo default class name inherited from the parent body's childclass attribute.

• Type: bool
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo Physics

ChildClassName

Child class name for this body.

• Type: FString
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo Physics
• Notes: Override-enabled (bOverride_ChildClassName)

SleepPolicy

Per-body sleep policy (MuJoCo 3.4+). Default lets the global option decide.

• Type: EMjBodySleepPolicy
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo Physics|Sleep

Private Properties

Property	Type	Description
m_Geoms	TArray<UMjGeom*>	Cached list of child Geoms for runtime binding.
m_Joints	TArray<UMjJoint*>	Cached list of child Joints for runtime binding.

m_Geoms

Cached list of child Geoms for runtime binding.

• Type: TArray<UMjGeom*>

m_Joints

Cached list of child Joints for runtime binding.

• Type: TArray<UMjJoint*>

Functions

Public Functions

General

Function	Returns	Description
RegisterToSpec()	void	Registers this body to the MuJoCo spec.
TickComponent()	void	Called every frame.
ImportFromXml()	void	Imports properties (Transform) directly from the raw XML node.
GetMj()	BodyView&	Semantic accessor for raw MuJoCo data and helper methods.

RegisterToSpec

Registers this body to the MuJoCo spec.

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

TickComponent

Called every frame.

• Signature: TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)

ImportFromXml

Imports properties (Transform) directly from the raw XML node.

• Signature: ImportFromXml(const class FXmlNode* Node)

GetMj

Semantic accessor for raw MuJoCo data and helper methods.

• Signature: GetMj()
• Returns: BodyView&

MuJoCo|Runtime

Function	Returns	Description
GetWorldPosition()	FVector	Gets this body's world position in Unreal Engine coordinates (cm).
GetWorldRotation()	FQuat	Gets this body's world rotation as a quaternion (UE convention).
GetSpatialVelocity()	FMuJoCoSpatialVelocity	Gets the body's spatial velocity in Unreal coordinates (cm/s and deg/s).
ApplyForce()	void	Applies an external wrench to this body for the next simulation step.
ClearForce()	void	Clears any external force/torque applied via ApplyForce on this body.

GetWorldPosition

Gets this body's world position in Unreal Engine coordinates (cm).

• Signature: GetWorldPosition()
• Blueprint: 🔵 Callable
• Returns: FVector

GetWorldRotation

Gets this body's world rotation as a quaternion (UE convention).

• Signature: GetWorldRotation()
• Blueprint: 🔵 Callable
• Returns: FQuat

GetSpatialVelocity

Gets the body's spatial velocity in Unreal coordinates (cm/s and deg/s).

• Signature: GetSpatialVelocity()
• Blueprint: 🔵 Callable
• Returns: FMuJoCoSpatialVelocity

ApplyForce

Applies an external wrench to this body for the next simulation step.

• Signature: ApplyForce(FVector Force, FVector Torque)
• Blueprint: 🔵 Callable

ClearForce

Clears any external force/torque applied via ApplyForce on this body.

• Signature: ClearForce()
• Blueprint: 🔵 Callable

MuJoCo|Sleep

Function	Returns	Description
IsAwake()	bool	Returns true if this body is currently awake (not sleeping).
Wake()	void	Wakes this body and its kinematic tree, forcing it out of sleep.
Sleep()	void	Forces this body and its kinematic tree to sleep immediately.

IsAwake

Returns true if this body is currently awake (not sleeping).

• Signature: IsAwake()
• Blueprint: 🔵 Callable 💎 Pure
• Returns: bool

Wake

Wakes this body and its kinematic tree, forcing it out of sleep.

• Signature: Wake()
• Blueprint: 🔵 Callable

Sleep

Forces this body and its kinematic tree to sleep immediately.

• Signature: Sleep()
• Blueprint: 🔵 Callable