Class Leap::Bone

class Leap.Bone : public IEquatable<Bone>

The Bone class represents a tracked bone.

All fingers contain 4 bones that make up the anatomy of the finger. Get valid Bone objects from a Finger object.

Bones are ordered from base to tip, indexed from 0 to 3. Additionally, the bone’s Type enum may be used to index a specific bone anatomically.

The thumb does not have a base metacarpal bone and therefore contains a valid, zero length bone at that location.

Since

2.0

Subclassed by Leap.Arm

Public Types

enum BoneType

Enumerates the type of bones.

Members of this enumeration are returned by Bone.Type() to identify a Bone object.

Since

2.0

Values:

TYPE_INVALID
TYPE_METACARPAL
TYPE_PROXIMAL
TYPE_INTERMEDIATE
TYPE_DISTAL

Public Functions

Bone ()

Constructs a default invalid Bone object.

Since

2.0

Bone (Vector prevJoint, Vector nextJoint, Vector center, Vector direction, float length, float width, Bone.BoneType type, LeapQuaternion rotation)

Constructs a new Bone object.

Since

3.0

bool Equals (Bone other)

Compare Bone object equality.

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

Since

2.0

override string ToString ()

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

Since

2.0

Public Members

Vector PrevJoint

The base of the bone, closest to the wrist. In anatomical terms, this is the proximal end of the bone.

Since

2.0

Vector NextJoint

The end of the bone, closest to the finger tip. In anatomical terms, this is the distal end of the bone.

Since

2.0

Vector Center

The midpoint of the bone.

Since

2.0

Vector Direction

The normalized direction of the bone from base to tip.

Since

2.0

float Length

The estimated length of the bone.

Since

2.0

float Width

The average width of the flesh around the bone.

Since

2.0

BoneType Type

The type of this bone.

Since

2.0

LeapQuaternion Rotation

The orientation of this Bone as a Quaternion.

Since

2.0

Properties

LeapTransform Basis { get; set; }

The orthonormal basis vectors for this Bone as a Matrix. The orientation of this Bone as a Quaternion.

Basis vectors specify the orientation of a bone.

xBasis Perpendicular to the longitudinal axis of the bone; exits the sides of the finger.

yBasis or up vector Perpendicular to the longitudinal axis of the bone; exits the top and bottom of the finger. More positive in the upward direction.

zBasis Aligned with the longitudinal axis of the bone. More positive toward the base of the finger.

The bases provided for the right hand use the right-hand rule; those for the left hand use the left-hand rule. Thus, the positive direction of the x-basis is to the right for the right hand and to the left for the left hand. You can change from right-hand to left-hand rule by multiplying the z basis vector by -1.

You can use the basis vectors for such purposes as measuring complex finger poses and skeletal animation.

Note that converting the basis vectors directly into a quaternion representation is not mathematically valid. If you use quaternions, create them from the derived rotation matrix not directly from the bases.

Since

2.0