Joints

static class

public static class Joints

Namespace: AR51.Unity.SDK

The canonical joint-index map for the position arrays returned by Skeleton.GetPositions<Vector3>() and Person.Positions. Every joint is a public const int index into those arrays; the class also exposes name↔index lookup tables and the line/connection data used to draw skeleton gizmos. The body layout is OpenPose-25 (indices 0–24); the hand joints follow, starting at RightWrist = 25.

Units

Joints itself holds only integer indices — no spatial data. The arrays it indexes (Person.Positions, Skeleton.GetPositions<Vector3>()) are Unity world-space Vector3 in meters.

Body joint indices (OpenPose-25)

The first 25 indices are the body, in OpenPose-25 order. CountWithoutHands is 25; CountWithHands is the full body + both hands (= LeftPinkyTip + 1).

public const int CountWithoutHands = 25;
public const int CountWithHands;   // = LeftPinkyTip + 1 (full body + both hands)

// Body (OpenPose-25 layout)
public const int Nose       = 0;
public const int Neck       = 1;
public const int RShoulder  = 2;
public const int RElbow     = 3;
public const int RWrist     = 4;
public const int LShoulder  = 5;
public const int LElbow     = 6;
public const int LWrist     = 7;
public const int MidHip     = 8;
public const int RHip       = 9;
public const int RKnee      = 10;
public const int RAnkle     = 11;
public const int LHip       = 12;
public const int LKnee      = 13;
public const int LAnkle     = 14;
public const int REye       = 15;
public const int LEye       = 16;
public const int REar       = 17;
public const int LEar       = 18;
public const int LBigToe    = 19;
public const int LSmallToe  = 20;
public const int LHeel      = 21;
public const int RBigToe    = 22;
public const int RSmallToe  = 23;
public const int RHeel      = 24;

// Hip aliases (both resolve to MidHip = 8)
public const int Hip  = MidHip;
public const int Hips = MidHip;

Hand joint indices

The hand joints begin immediately after the body at RightWrist = 25, then run per finger in Proximal → Middle → Distal → Tip order; the left hand follows the right. Each finger group is exposed twice — once with descriptive names and once with anatomical aliases:

Descriptive	Anatomical alias
RightIndexProximal	RIndex1Knuckles
RightIndexMiddle	RIndex2PIP
RightIndexDistal	RIndex3DIP
RightIndexTip	RIndex4FingerTip
… (same pattern for thumb / middle / ring / pinky, both hands)	…

Per-finger offset constants (added to a hand's wrist index to reach that finger's first joint):

public const int ThumbOffset  = 1;
public const int IndexOffset  = 5;
public const int MiddleOffset = 9;
public const int RingOffset   = 13;
public const int PinkyOffset  = 17;

Spine / clavicle indices are also defined: LClavicle, RClavicle, and Spine0…Spine6.

⚠️ Two distinct hand-joint schemes

These body-array hand indices (Joints, starting RightWrist = 25) are not the same enumeration as the device hand-tracking HandJointType, which indexes HandJointInfo[] from Wrist = 0. Use Joints for the full-body skeleton arrays; use HandJointType for the hands-adapter arrays.

Helper data

Static tables used for drawing and grouping joints.

Member	Type	Description
Drawing
JointLines	JointLine[]	colored from→to pairs for drawing the skeleton
GizmoLineConnections	int[][]	bone connections used to draw the skeleton gizmo
Grouped indices
FootJointIndices	int[]	{ LHeel, LBigToe, LSmallToe, RHeel, RBigToe, RSmallToe }
HeadJoints	List<int>	{ Nose, REye, LEye, REar, LEar }
HandWristPairs	int[]	wrist-pair indices for the hands
HandStrips	int[]	per-finger strip indices for the hands
RightLeftOffset	int[]	{ RightWrist, LeftWrist } — base index of each hand
Lookup
JointByString	Dictionary<string,int>	name → index
NameByJointIndex	Dictionary<int,string>	index → name

Method summary

Method	Returns
GetJointName	string	static
Parse	int	static

→ Full descriptions in Method details below.

Method details

GetJointName

methodstatic

public static string GetJointName(int jointIndex);

The display name for a joint index (the reverse of Parse). Backed by NameByJointIndex.

Parameters

jointIndexinta joint index (a Joints constant, e.g. Joints.RWrist)

Returnsstringthe joint's name (e.g. "RWrist")

Exampleinferred

foreach (var person in SkeletonConsumer.Instance.Persons)
{
    Vector3 head = person.GetPosition(Joints.Nose);   // meters
    Debug.Log($"{Joints.GetJointName(Joints.Nose)} at {head}");
}

Parse

methodstatic

public static int Parse(string s);

Resolve a joint name to its index (the reverse of GetJointName). Backed by JointByString.

Parameters

sstringa joint name (e.g. "RWrist")

Returnsintthe matching joint index, or -1 if the name is unknown

Nested types

JointLine

property

public struct JointLine
{
    public int From;
    public int To;
    public Color Color;
    public JointLine(int from, int to, Color color);
}

A single colored bone segment: two joint indices and the Color to draw it in. The JointLines table is an array of these, consumed by the skeleton-drawing helpers.

HandJoints

sealed class Unity component

public sealed class HandJoints : MonoBehaviour

Namespace: AR51.Unity.SDK

A MonoBehaviour marker component placed on a hand-joint hierarchy. It is a separate type from the static Joints index map above.

⚠️ needs confirmation

HandJoints has an empty body — no public members in this version; it appears to exist only as a tag/marker on a hand-joint hierarchy. Confirm its intended role before relying on it.

See also

• Skeleton — the per-frame payload whose GetPositions<Vector3>() buffer these indices address
• Person — exposes Positions / GetPosition(int) indexed by these constants
• HandJointType — the separate device hand-tracking joint enumeration (Wrist = 0)
• Skeletons & characters — area overview
• Class index — all Unity SDK types