為了在我們的VR項目中增添有用功能，就添加了這個模塊。

無人機的操控是模擬現實無人機的雙搖桿手柄操作方式，對htc vive兩個手柄的touchpad的功能進行繼承重寫，實現操控：

如圖，左touchpad分成四個區域，根據touchpad的觸摸檢測觸碰位置的區域，同時根據按壓touchpad來執行操控。分別對應的：水平軸左右轉向，以及豎直軸上升下降。

而右touchpad根據觸摸位置相對圓中心的向量方向，來控制飛行器水平面上的位移方向，為了效果更真實，還設置了加速度。

下面來看一下代碼：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Flying : MonoBehaviour {

	public bool IsFlying = false;

	public GameObject leftController;
	public GameObject rightController;

	public float maxVelocityXZ=2.0f;
	public float velocityY=1.0f;
	public float accelerationXZ=10.0f;

	private float velocityXZ=0;

	SteamVR_TrackedObject trackedLeft;
	SteamVR_TrackedObject trackedRight;
	Vector3 right;

	void Awake(){
		trackedLeft = leftController.GetComponent<SteamVR_TrackedObject> ();
		trackedRight = rightController.GetComponent<SteamVR_TrackedObject> ();
	}
	// Use this for initialization
	void Start () {

	}
	
	// Update is called once per frame
	void Update () {
		var deviceLeft = SteamVR_Controller.Input ((int)trackedLeft.index);
		var deviceRight = SteamVR_Controller.Input ((int)trackedRight.index);
		if (IsFlying == true) {
			
			if(deviceLeft.GetPress(SteamVR_Controller.ButtonMask.Touchpad)){
				Vector2 left = deviceLeft.GetAxis ();
				float angle = VectorAngle (new Vector2 (1, 0), left);
				if (angle > 45 && angle < 135) {//上
					transform.Translate (Vector3.down * velocityY*Time.deltaTime);
				}
				if(angle<-45&&angle>-135){//下
					transform.Translate (Vector3.up * velocityY*Time.deltaTime);
				}
				if((angle<180&&angle>135)||(angle<-135&&angle>-180)){
					transform.Rotate (Vector3.down * Time.deltaTime*150);
				}
				if ((angle < 45 && angle > 0) || (angle <0 && angle > -45)) {
					transform.Rotate (Vector3.up * Time.deltaTime*150);
				}
			}
			if(deviceRight.GetPress(SteamVR_Controller.ButtonMask.Touchpad)){
				if (velocityXZ < maxVelocityXZ) {
					velocityXZ += accelerationXZ * Time.deltaTime;
				}
				Vector2 rightTouchPad = deviceRight.GetAxis ();
				right = new Vector3 (rightTouchPad.x,0, rightTouchPad.y);
				transform.Translate (velocityXZ * Time.deltaTime * right.normalized);
			}
			if(velocityXZ>0&&!deviceRight.GetPress(SteamVR_Controller.ButtonMask.Touchpad)){
				velocityXZ -= accelerationXZ * Time.deltaTime;
				transform.Translate (velocityXZ * Time.deltaTime * right.normalized);
			}
			//transform.Rotate (Vector3.Cross (Vector3.up, right) * velocityXZ,Space.World);

	}

	}

		float VectorAngle(Vector2 from, Vector2 to)
	{  
		float angle;  
		Vector3 cross = Vector3.Cross(from, to);  
		angle = Vector2.Angle(from, to);  
		return cross.z > 0 ? -angle : angle;  
	}  
}

到這里我們對于用touchpad控制無人機的飛行就完成了。但是touchpad在普通場景里用于控制手柄發出射線進行碰撞檢測來實現 傳送位移。因此我們再直升機室里加了一個cube當做trigger，通過手柄扳機觸發來進入飛行狀態，飛行狀態時，向前面的代碼的bool值IsFlying傳值為true，同時將手柄上的VRTK_SimplePointer組件的enable設置為false，這樣就不會發出射線了。

下面是綁在這個觸發器Cube上的代碼：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using VRTK;

public class FlyingTrigger : VRTK_InteractableObject {

	public GameObject airVehicle;
	public Transform airVehiclePos;

	[Header("ControllerDevices", order = 1)]
	public GameObject controllerLeft;
	public GameObject controllerRight;

	VRTK_SimplePointer pointerLeft;
	VRTK_SimplePointer pointerRight;
	// Use this for initialization
	public override void StartUsing(GameObject usingObject)
	{
		base.StartUsing(usingObject);
		airVehicle.GetComponent<Flying> ().IsFlying = true;
		pointerLeft.enabled = false;
		pointerRight.enabled = false;
	}

	public override void StopUsing(GameObject usingObject)
	{
		base.StopUsing(usingObject);
		airVehicle.GetComponent<Flying> ().IsFlying = false;
		pointerLeft.enabled = true;
		pointerRight.enabled = true;
		airVehicle.transform.position = airVehiclePos.position;

	}

	protected override void Start()
	{
		base.Start();
	}

	protected override void Awake()
	{
		base.Awake ();
		pointerLeft = controllerLeft.GetComponent<VRTK_SimplePointer> ();
		pointerRight = controllerRight.GetComponent<VRTK_SimplePointer> ();
	}
}

這樣一來就實現了無人機模擬操縱的功能，最后將資源都搭好放置在一個房間里。