BoneTransform

C++ class C++ only

class AR51SDK_API BoneTransform;

A handle to a single bone of a UPoseableMeshComponent, carrying a cached bind-pose (init) transform. The IK solver and the character's finger-joint accessors (UAR51Character::GetLeftHandJoints() / GetRightHandJoints()) hand these out so you can read or override a bone's pose, then push the result back onto the mesh with Apply().

C++ only

BoneTransform is not Blueprint-exposed (no UFUNCTION/UPROPERTY reflection). It is callable from C++ only.

Units & space

All positions are in centimetres, all rotations in degrees, and world reads/writes are in UE world space (per EBoneSpaces::WorldSpace). AR 51 mocap data is metres — convert at the boundary if you mix the two.

Identity

Member	Type	Description
BoneIndex	int	the bone's index within the UPoseableMeshComponent
BoneName	FName	the bone's skeleton name

Method summary

Bind-pose reads (the cached init transform)

Method	Returns
initLocalPosition / initLocalRotation / initLocalScale	FVector / FQuat	C++ only
initPosition / initRotation / initScale	FVector / FQuat	C++ only

World read/write

Method	Returns
position / rotation / lossyScale	FVector / FQuat	C++ only
localToWorldMatrix / worldToLocalMatrix	FMatrix	C++ only
SetPosition / SetRotation / SetLossyScale	void	C++ only

Local read/write

Method	Returns
localPosition / localRotation / localScale	FVector / FQuat	C++ only
SetLocalPosition / SetLocalRotation / SetLocalScale	void	C++ only

Hierarchy & commit

Method	Returns
Apply	void	C++ only
GetParnet (sic)	BoneTransform	C++ only
SetParent	void	static · C++ only
GetChildren / GetChild / GetChildOrNull	…	C++ only

→ Full descriptions in Method details below.

Method details

Bind-pose reads

methodC++ only

FVector initLocalPosition() const;
FQuat   initLocalRotation() const;
FVector initLocalScale()    const;

FVector initPosition() const;   // world
FQuat   initRotation() const;   // world
FVector initScale()    const;   // world

The bone's bind-pose (rest) transform, captured when the handle was created — both in the bone's local space (initLocal…) and in UE world space (init…). Use these as the reference pose to compute offsets against the live pose.

ReturnsFVector / FQuatthe cached init position (cm), rotation (degrees, as a quaternion), or scale

World read/write

methodC++ only

FVector position()   const;   // UE world space, cm
FQuat   rotation()   const;   // UE world space
FVector lossyScale() const;   // accumulated world scale

FMatrix localToWorldMatrix() const;
FMatrix worldToLocalMatrix() const;

void SetPosition(const FVector& WorldPosition);
void SetRotation(const FQuat&   WorldRotation);
void SetLossyScale(const FVector& WorldScale);

Read or override the bone's current pose in UE world space (centimetres / degrees). lossyScale() is the non-recoverable accumulated world scale (matching Unity's Transform.lossyScale). The two matrix getters give the bone's full world transform and its inverse.

Setters stage the new value; nothing reaches the mesh until you call Apply().

Parameters

WorldPositionFVectortarget world position, cm

WorldRotationFQuattarget world rotation

WorldScaleFVectortarget world scale

Exampleinferred

// Nudge a finger joint 1 cm along world +Z, then commit
for (const TSharedPtr<BoneTransform>& Joint : Character->GetRightHandJoints())
{
    Joint->SetPosition(Joint->position() + FVector(0, 0, 1.f));   // UE cm
    Joint->Apply();
}

Local read/write

methodC++ only

FVector localPosition() const;
FQuat   localRotation() const;
FVector localScale()    const;

void SetLocalPosition(const FVector& LocalPosition);
void SetLocalRotation(const FQuat&   LocalRotation);
void SetLocalScale(const FVector&    LocalScale);

Same as the world accessors but relative to the bone's parent. Local rotation is the value you usually animate per-joint (e.g. finger curl). Setters stage the value; call Apply() to push it to the mesh.

Parameters

LocalPositionFVectorparent-relative position, cm

LocalRotationFQuatparent-relative rotation

LocalScaleFVectorparent-relative scale

Apply

methodC++ only

void Apply();

Finalizes the staged transform onto the underlying UPoseableMeshComponent. The Set… calls only update this handle's working state — Apply() is what makes the change visible on the mesh. Call it once per bone after staging all the position/rotation/scale you want.

Hierarchy

methodC++ only

BoneTransform GetParnet() const;   // (sic) — spelled "GetParnet" in the SDK
static void   SetParent(BoneTransform& parent, BoneTransform& child);

TArray<BoneTransform> GetChildren() const;
BoneTransform         GetChild(int i) const;
BoneTransform         GetChildOrNull(int i) const;

Walk or rewire the bone hierarchy. GetParnet() returns the parent bone handle (note the SDK's misspelling). SetParent is static — it reparents child under parent. GetChild(i) indexes a child directly; GetChildOrNull(i) is the bounds-safe variant that returns an invalid/empty handle instead of asserting when i is out of range.

Parameters

iintchild index

ReturnsBoneTransformthe requested parent or child bone handle

---

TTransform

C++ class C++ only

class AR51SDK_API TTransform;

A Unity-Transform-style wrapper over an AActor / USceneComponent. It exists to make porting Unity code to Unreal easier: it exposes the same position / localPosition / eulerAngles / parent / GetChild surface a Unity developer expects, mapped onto UE actors and scene components. It is a convenience utility — not part of the mocap data path.

C++ only

TTransform is not Blueprint-exposed. It is callable from C++ only.

Units

UE units throughout — positions in centimetres, rotations in degrees. (Unity code being ported uses metres/degrees; convert positions when bridging.)

Method summary

Transform read/write

Method	Returns
position / localPosition (+ setters)	FVector	C++ only
rotation / localRotation (+ setters)	FQuat	C++ only
eulerAngles / localEulerAngles (+ setters)	FVector	C++ only
localScale / lossyScale (+ setter)	FVector	C++ only
localToWorldMatrix / worldToLocalMatrix	FMatrix	C++ only

Hierarchy

Method	Returns
GetParent / SetParent	TTransform / void	C++ only
GetRoot	TTransform	C++ only
GetChildren / GetChild	…	C++ only
DFS	…	C++ only

Utility

Method	Returns
IsValid	bool	C++ only
GetName / SetName	FString / void	C++ only

→ Full descriptions in Method details below.

Method details

Transform read/write

methodC++ only

// World
FVector position()      const;   void SetPosition(const FVector&);     // cm
FQuat   rotation()      const;   void SetRotation(const FQuat&);
FVector eulerAngles()   const;   void SetEulerAngles(const FVector&);  // degrees
FVector lossyScale()    const;

// Local
FVector localPosition()   const; void SetLocalPosition(const FVector&);
FQuat   localRotation()   const; void SetLocalRotation(const FQuat&);
FVector localEulerAngles()const; void SetLocalEulerAngles(const FVector&);
FVector localScale()      const; void SetLocalScale(const FVector&);

// Matrices
FMatrix localToWorldMatrix() const;
FMatrix worldToLocalMatrix() const;

The full Unity-style transform surface, in both world and local space, mapped onto the wrapped actor/scene component. Euler getters/setters mirror Unity's eulerAngles / localEulerAngles (degrees); lossyScale() is the accumulated world scale. Unlike BoneTransform there is no Apply() — writes go straight to the underlying USceneComponent.

Exampleinferred

// Port of a Unity snippet: face the world origin
TTransform T(MyActor);
const FVector Dir = (FVector::ZeroVector - T.position()).GetSafeNormal();
T.SetRotation(FRotationMatrix::MakeFromX(Dir).ToQuat());

Hierarchy

methodC++ only

TTransform            GetParent() const;
void                  SetParent(const TTransform& parent);
TTransform            GetRoot() const;
TArray<TTransform>    GetChildren() const;
TTransform            GetChild(int i) const;
TArray<TTransform>    DFS() const;

Navigate or rewire the scene-graph the way Unity's Transform does. GetRoot() returns the topmost ancestor; DFS() returns the subtree flattened in depth-first order (root first), handy when porting Unity hierarchy traversals.

Parameters

iintchild index

parentTTransformthe new parent to attach under

ReturnsTTransformthe requested parent, root, or child wrapper

Utility

methodC++ only

bool    IsValid() const;
FString GetName() const;
void    SetName(const FString& name);

IsValid() reports whether the wrapper still points at a live actor/component — check it before dereferencing a handle you have held across frames. GetName / SetName read and set the wrapped object's name.

Returnsbooltrue while the wrapped actor/component is valid

See also

• UAR51Character — hands out BoneTransform finger-joint handles via GetLeftHandJoints() / GetRightHandJoints()
• USkeletonConsumer — the consumer that drives the characters whose bones these handles wrap
• Utilities & platform — other C++ helper/adapter types
• Class index — all Unreal SDK types