Unigine::LeapMotion::Bone Struct

Header:

#include <LeapMotionInterface.h>

Variables:

Name	Description
Bone::TYPE_METACARPAL	Metacarpal bone. A bone connected to the wrist inside the palm.
Bone::TYPE_PROXIMAL	Proximal bone. A bone connecting to the palm.
Bone::TYPE_INTERMEDIATE	Intermediate bone. A bone between the tip and the base.
Bone::TYPE_DISTAL	Distal bone. A bone at the tip of the finger.
Bone::BONE_NUM_TYPES	Total number of bone types.

Notice

LeapMotion plugin must be loaded.

This structure represents a bone of a finger and has the following set of properties:

type	Bone type. One of the Bone::TYPE_* values.
length	Length of the bone, in meters.
witdh	Width of the bone, in meters.
is_valid	Indicates whether the bone contains valid tracking data (1).
prev_joint	Coordinates of the end of the bone, closest to the wrist (proximal).
next_joint	Coordinates of the end of the bone, closest to the finger tip (distal).
center	Coordinates of the center of the bone.
direction	Normalized direction of the bone from wrist to tip.
basis	Orthonormal basis vectors for the bone as a Matrix. Basis vectors specify the orientation of the bone: X - Perpendicular to the longitudinal axis of the bone; exits the sides of the finger. Y (or up vector) - Perpendicular to the longitudinal axis of the bone; exits the top and bottom of the finger. Increases in the upward direction. Z - Aligned with the longitudinal axis of the bone. Increases 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. Notice 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.

Notice

All coordinates are relative to the origin of the Leap Motion coordinate system.

The Bone structure is declared as follows:

Source code (C++)

struct Bone
{
	int type;
	float length;
	float width;
	int is_valid;
	Unigine::Math::vec3 prev_joint;
	Unigine::Math::vec3 next_joint;
	Unigine::Math::vec3 center;
	Unigine::Math::vec3 direction;
	Unigine::Math::mat4 basis;
};

Last update: 2020-01-14

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