Class Leap::Hand

class Leap.Hand : public IEquatable<Hand>

The Hand class reports the physical characteristics of a detected hand.

Hand tracking data includes a palm position and velocity; vectors for the palm normal and direction to the fingers; and lists of the attached fingers.

Note that Hand objects can be invalid, which means that they do not contain valid tracking data and do not correspond to a physical entity. Invalid Hand objects can be the result of using the default constructor, or modifying the hand data in an incorrect way.

Since

1.0

Public Functions

Hand ()

Constructs a Hand object.

An uninitialized hand is considered invalid. Get valid Hand objects from a Frame object.

Since

1.0

Hand (long frameID, int id, float confidence, float grabStrength, float pinchStrength, float pinchDistance, float palmWidth, bool isLeft, float timeVisible, Arm arm, Finger[] fingers, Vector3 palmPosition, Vector3 stabilizedPalmPosition, Vector3 palmVelocity, Vector3 palmNormal, Quaternion palmOrientation, Vector3 direction, Vector3 wristPosition)

Constructs a hand.

Generally, you should not create your own Hand objects. Such objects will not have valid tracking data. Get valid Hand objects from a frame received from the service.

bool Equals (Hand other)

Compare Hand object equality.

Two Hand objects are equal if and only if both Hand objects represent the exact same physical hand in the same frame and both Hand objects are valid.

override string ToString ()

A string containing a brief, human readable description of the Hand object.

Since

1.0

Public Members

int Id

A unique ID assigned to this Hand object, whose value remains the same across consecutive frames while the tracked hand remains visible. If tracking is lost (for example, when a hand is occluded by another hand or when it is withdrawn from or reaches the edge of the Leap Motion Controller field of view), the Leap Motion software may assign a new ID when it detects the hand in a future frame.

Use the ID value with the Frame.Hand() function to find this Hand object in future frames.

Since

1.0

Finger[] fingers = new Finger[5]

The list of Finger objects detected in this frame that are attached to this hand, given in order from thumb to pinky. The list cannot be empty.

Since

1.0

Vector3 PalmPosition

The center position of the palm.

Since

1.0

Vector3 PalmVelocity

The rate of change of the palm position.

Since

1.0

Vector3 PalmNormal

The normal vector to the palm. If your hand is flat, this vector will point downward, or “out” of the front surface of your palm.

The direction is expressed as a unit vector pointing in the same direction as the palm normal (that is, a vector orthogonal to the palm).

You can use the palm normal vector to compute the roll angle of the palm with respect to the horizontal plane.

Since

1.0

Vector3 Direction

The direction from the palm position toward the fingers.

The direction is expressed as a unit vector pointing in the same direction as the directed line from the palm position to the fingers.

You can use the palm direction vector to compute the pitch and yaw angles of the palm with respect to the horizontal plane.

Since

1.0

Quaternion Rotation

The rotation of the hand as a quaternion.

Since

3.1

float GrabStrength

The strength of a grab hand pose.

The strength is zero for an open hand, and blends to one when a grabbing hand pose is recognized.

Since

2.0

float PinchStrength

The holding strength of a pinch hand pose.

The strength is zero for an open hand, and blends to one when a pinching hand pose is recognized. Pinching can be done between the thumb and any other finger of the same hand.

Since

2.0

float PinchDistance

The distance between the thumb and index finger of a pinch hand pose.

The distance is computed by looking at the shortest distance between the last 2 phalanges of the thumb and those of the index finger. This pinch measurement only takes thumb and index finger into account.

Since

3.0

float PalmWidth

The estimated width of the palm when the hand is in a flat position.

Since

2.0

Vector3 StabilizedPalmPosition

The stabilized palm position of this Hand.

Smoothing and stabilization is performed in order to make this value more suitable for interaction with 2D content. The stabilized position lags behind the palm position by a variable amount, depending primarily on the speed of movement.

Since

1.0

Vector3 WristPosition

The position of the wrist of this hand.

Since

2.0.3

float TimeVisible

The duration of time this Hand has been visible to the Leap Motion Controller, in seconds

Since

1.0

float Confidence

How confident we are with a given hand pose. The confidence level ranges between 0.0 and 1.0 inclusive.

Since

2.0

bool IsLeft

Identifies whether this Hand is a left hand.

Since

2.0

Arm Arm

The arm to which this hand is attached.

If the arm is not completely in view, Arm attributes are estimated based on the attributes of entities that are in view combined with typical human anatomy.

Since

2.0.3

Properties

LeapTransform Basis { get; set; }

The transform of the hand.

Note, in version prior to 3.1, the Basis was a Matrix object.

Since

3.1

bool IsRight { get; set; }

Identifies whether this Hand is a right hand.

Since

2.0