LeapBone Class Reference

The LeapBone class represents a tracked bone. More...

Inherits NSObject.

Properties
LeapMatrix *	basis
	The orientation of the bone as a basis matrix. More...
LeapVector *	center
	The midpoint in the center of the bone. More...
LeapVector *	direction
	The normalized direction of the bone from base to tip. More...
LeapBone *	invalid
	An invalid Bone object. More...
BOOL	isValid
	Reports whether this is a valid LeapBone object. More...
float	length
	The estimated length of the bone in millimeters. More...
LeapVector *	nextJoint
	The end of the bone farthest from the wrist. More...
LeapVector *	prevJoint
	The end of the bone closest from the wrist. More...
LeapBoneType	type
	The name of this bone. More...
float	width
	The average width of the finger along this bone in millimeters. More...

Detailed Description

The LeapBone class represents a tracked bone.

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

Bones are ordered from base to tip, indexed from 0 to 3. Additionally, the bone's LeapBoneType 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.

Note that LeapBone objects can be invalid, which means that they do not contain valid tracking data and do not correspond to a physical bone. Invalid LeapBone objects can be the result of asking for a LeapBone object from an invalid finger, indexing a bone out of range, or constructing a new bone. Test for validity with the LeapBone.isValid property.

Since 2.0

Property Documentation

- (LeapMatrix*) basis

readnonatomicassign

The orientation of the bone as a basis matrix.

The basis is defined as follows: xAxis: Clockwise rotation axis of the bone yAxis: Positive above the bone zAxis: Positive along the bone towards the wrist

LeapMatrix *basis = bone.basis;

Note: Since the left hand is a mirror of the right hand, left handed bones will contain a left-handed basis.

Returns

The basis of the bone as a matrix.

Since

2.0

- (LeapVector*) center

readnonatomicassign

The midpoint in the center of the bone.

LeapVector *center = bone.center;

Returns

The midpoint in the center of the bone.

Since

2.0

- (LeapVector*) direction

readnonatomicassign

The normalized direction of the bone from base to tip.

LeapVector *direction = bone.direction;

Returns

The normalized direction of the bone from base to tip.

Since

2.0

- (LeapBone*) invalid

readnonatomicassign

An invalid Bone object.

You can use an invalid LeapBone object in comparisons testing whether a given LeapBone instance is valid or invalid. (You can also use the LeapBone.isValid property.)

- (LeapBone *)findBone:(NSString *) criteria
{
    //Look up bone with criteria, else
    return LeapBone.invalid;
}

Returns

The invalid LeapBone instance.

Since

2.0

- (BOOL) isValid

readnonatomicassign

Reports whether this is a valid LeapBone object.

if( bone.isValid){
    //Use the bone...
}

Since

2.0

- (float) length

readnonatomicassign

The estimated length of the bone in millimeters.

float length = bone.length;

Returns

The length of the bone in millimeters.

Since

2.0

- (LeapVector*) nextJoint

readnonatomicassign

The end of the bone farthest from the wrist.

LeapVector *distalEnd = bone.nextJoint;

Returns

The LeapVector containing the coordinates of the next joint position (the joint or bone tip closest to the end of the finger).

Since

2.0

- (LeapVector*) prevJoint

readnonatomicassign

The end of the bone closest from the wrist.

LeapVector *proximalEnd = bone.prevJoint;

Returns

The LeapVector containing the coordinates of the previous joint position (the joint closer to the wrist).

Since

2.0

- (LeapBoneType) type

readnonatomicassign

The name of this bone.

LeapBoneType boneDesignator = bone.type;

Returns

The anatomical type of this bone as a member of the LeapBoneType enumeration.

Since

2.0

- (float) width

readnonatomicassign

The average width of the finger along this bone in millimeters.

float width = bone.width;

Returns

The average width of the bone including the surrounding flesh in millimeters.

Since

2.0