Unigine.Plugins.LeapMotion.Bone Struct
Notice
LeapMotion plugin must be loaded.
This structure represents a bone of a finger. All coordinates are relative to the origin of the Leap Motion coordinate system.
The Bone structure is declared as follows:
Source code (C#)
public struct Bone
{
public enum TYPE
{
METACARPAL = 0, // Bone connected to the wrist inside the palm
PROXIMAL = 1, // Bone connecting to the palm
INTERMEDIATE = 2, // Bone between the tip and the base
DISTAL = 3, // Bone at the tip of the finger
NUM_TYPES,
};
public int type;
public float length;
public float width;
public int is_valid;
public vec3 prev_joint;
public vec3 next_joint;
public vec3 center;
public vec3 direction;
public mat4 basis;
};struct
Fields
- enum TYPE - For example, to specify the proximal bone, write Bone.TYPE.PROXIMAL.
- int type - Bone type. One of the TYPE values.
- float length - Length of the bone, in meters.
- float width - Width of the bone, in meters.
- int is_valid - Value indicating if the bone contains valid tracking data.
- vec3 prev_joint - Coordinates of the end of the bone, closest to the wrist (proximal).
NoticeAll coordinates are relative to the origin of the Leap Motion coordinate system.
- vec3 next_joint - Coordinates of the end of the bone, closest to the finger tip (distal).
NoticeAll coordinates are relative to the origin of the Leap Motion coordinate system.
- vec3 center - Coordinates of the center of the bone.
NoticeAll coordinates are relative to the origin of the Leap Motion coordinate system.
- vec3 direction - Normalized direction of the bone from wrist to tip.
NoticeAll coordinates are relative to the origin of the Leap Motion coordinate system.
- mat4 basis - Orthonormal basis vectors for this Bone as a Matrix.
Basis vectors specify the orientation of a 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.
NoticeConverting 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.
Last update:
2024-10-21
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