Unigine::Plugins::LeapMotion::Arm Struct

struct Arm

Fields

• float width - Width of the forearm, in meters.
• int is_valid - Value indicating if the arm contains valid tracking data.
• Math::vec3 direction - Normalized direction in which the arm is pointing (from elbow to wrist).
  Notice

  All coordinates are relative to the origin of the Leap Motion coordinate system.
• Math::vec3 elbow_position - Coordinates of the elbow position.
  Notice

  All coordinates are relative to the origin of the Leap Motion coordinate system.
• Math::vec3 wrist_position - Coordinates of the end of the bone, closest to the finger tip (distal).
  Notice

  All coordinates are relative to the origin of the Leap Motion coordinate system.
• Math::vec3 center - Coordinates of the center of the forearm.
  Notice

  All coordinates are relative to the origin of the Leap Motion coordinate system.
• Math::mat4 basis - Orthonormal basis vectors for the arm as a Matrix.

  Basis vectors specify the orientation of the arm bone:

  • X - Perpendicular to the longitudinal axis of the arm bone; exits the arm laterally through the sides of the wrist.
  • Y (or up vector) - Perpendicular to the longitudinal axis of the arm bone; exits the top and bottom of the arm. Increases in the upward direction.
  • Z - Aligned with the longitudinal axis of the arm bone. Increases toward the wrist.

  The bases provided for the right arm use the right-hand rule; those for the left arm use the left-hand rule. Thus, the positive direction of the x-basis is to the right for the right arm and to the left for the left arm. 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.