--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Orchestland/Assets/LeapMotion/DemoResources/Scripts/AerodynamicLeaf.cs	Fri Jul 17 23:23:43 2015 +0900
@@ -0,0 +1,104 @@
+/******************************************************************************\
+* Copyright (C) Leap Motion, Inc. 2011-2014.                                   *
+* Leap Motion proprietary. Licensed under Apache 2.0                           *
+* Available at http://www.apache.org/licenses/LICENSE-2.0.html                 *
+\******************************************************************************/
+
+using UnityEngine;
+using System.Collections;
+
+public class AerodynamicLeaf : MonoBehaviour {
+
+  public float airDragForce = 0.2f;
+  public float airDragTorque = 0.001f;
+
+  // Air to water transition level.
+  public float waterHeight = 0.0f;
+  public float transitionWidth = 0.2f;
+
+  // Water drag.
+  public float waterDrag = 5.0f;
+  public float waterAngularDrag = 10.0f;
+
+  // Water forces.
+  public float waterBuoancyForce = 0.1f;
+  public float waterDragTorque = 0.002f;
+  public float waterDragForce = 0.002f;
+  public float waterSurfaceTorque = 0.002f;
+
+  // Water curent.
+  public Vector3 waterCurrentVelocity;
+  public float waterCurrentForce = 0.1f;
+
+  private float air_drag_;
+  private float air_angular_drag_;
+  private float drag_force_;
+  private float drag_torque_;
+
+  void Start() {
+    air_drag_ = GetComponent<Rigidbody>().drag;
+    air_angular_drag_ = GetComponent<Rigidbody>().angularDrag;
+    drag_force_ = airDragForce;
+    drag_torque_ = airDragTorque;
+  }
+
+  void DragUpdate() {
+    Vector3 velocity = GetComponent<Rigidbody>().velocity;
+    Vector3 normal = transform.up;
+
+    float dot = Vector3.Dot(velocity, normal);
+    GetComponent<Rigidbody>().AddForce(-normal * drag_force_ * dot);
+
+    Vector3 cross = Vector3.Cross(velocity, normal);
+    GetComponent<Rigidbody>().AddTorque(-drag_torque_ * cross);
+  }
+
+  void AirUpdate() {
+    GetComponent<Rigidbody>().drag = air_drag_;
+    GetComponent<Rigidbody>().angularDrag = air_angular_drag_;
+    drag_force_ = airDragForce;
+    drag_torque_ = airDragTorque;
+    DragUpdate();
+  }
+
+  void WaterUpdate(float level) {
+    GetComponent<Rigidbody>().drag = waterDrag;
+    GetComponent<Rigidbody>().angularDrag = waterAngularDrag;
+
+    drag_force_ = waterDragForce;
+    drag_torque_ = waterDragTorque;
+    DragUpdate();
+
+    float transition = Mathf.Clamp(-level / transitionWidth, 0.0f, 1.0f);
+    GetComponent<Rigidbody>().AddForce(new Vector3(0, waterBuoancyForce * transition, 0));
+
+    if (Vector3.Dot(transform.up, Vector3.up) >= 0) {
+      Vector3 torque_vector = Vector3.Cross(transform.up, Vector3.up);
+      GetComponent<Rigidbody>().AddTorque((1 - transition) * waterSurfaceTorque * torque_vector);
+    }
+    else {
+      Vector3 torque_vector = Vector3.Cross(-transform.up, Vector3.up);
+      GetComponent<Rigidbody>().AddTorque((1 - transition) * waterSurfaceTorque * torque_vector);
+    }
+
+    // Running water current.
+    Vector3 delta_current = waterCurrentVelocity - GetComponent<Rigidbody>().velocity;
+    delta_current.y = 0;
+    GetComponent<Rigidbody>().AddForce(waterCurrentForce * delta_current);
+  }
+  
+  float UnitsAboveWater() {
+    return transform.position.y - waterHeight;
+  }
+
+  public bool TouchingWater() {
+    return UnitsAboveWater() < 0;
+  }
+
+  void FixedUpdate() {
+    if (TouchingWater())
+      WaterUpdate(UnitsAboveWater());
+    else
+      AirUpdate();
+  }
+}