1、我们先来将SteamVR_Unity_Toolkit.unitypackage这个包导入，Asset Store里免费下载
2、当Unity熟练到一定程度，事件与委托是必备的基础！所以本文默认我们已经走过基础阶段。交互设计的精华也在于事件与委托的巧妙设计与实现。VR里的交互更不例外
这篇博客，从SteamVR_Unity_Toolkit的代码里剖析下，它是怎么封装SteamVR的事件的。
3、看类VRTK_ControllerEvents.cs
namespace VRTK { using UnityEngine; using System.Collections; public struct ControllerInteractionEventArgs { public uint controllerIndex; public float buttonPressure; public Vector2 touchpadAxis; public float touchpadAngle; } public delegate void ControllerInteractionEventHandler(object sender, ControllerInteractionEventArgs e); public class VRTK_ControllerEvents : MonoBehaviour { public enum ButtonAlias { Trigger, Grip, Touchpad_Touch, Touchpad_Press, Application_Menu } public ButtonAlias pointerToggleButton = ButtonAlias.Grip; public ButtonAlias grabToggleButton = ButtonAlias.Trigger; public ButtonAlias useToggleButton = ButtonAlias.Trigger; public ButtonAlias menuToggleButton = ButtonAlias.Application_Menu; public int axisFidelity = 1; public bool triggerPressed = false; public bool triggerAxisChanged = false; public bool applicationMenuPressed = false; public bool touchpadPressed = false; public bool touchpadTouched = false; public bool touchpadAxisChanged = false; public bool gripPressed = false; public bool pointerPressed = false; public bool grabPressed = false; public bool usePressed = false; public bool menuPressed = false; public event ControllerInteractionEventHandler TriggerPressed; public event ControllerInteractionEventHandler TriggerReleased; public event ControllerInteractionEventHandler TriggerAxisChanged; public event ControllerInteractionEventHandler ApplicationMenuPressed; public event ControllerInteractionEventHandler ApplicationMenuReleased; public event ControllerInteractionEventHandler GripPressed; public event ControllerInteractionEventHandler GripReleased; public event ControllerInteractionEventHandler TouchpadPressed; public event ControllerInteractionEventHandler TouchpadReleased; public event ControllerInteractionEventHandler TouchpadTouchStart; public event ControllerInteractionEventHandler TouchpadTouchEnd; public event ControllerInteractionEventHandler TouchpadAxisChanged; public event ControllerInteractionEventHandler AliasPointerOn; public event ControllerInteractionEventHandler AliasPointerOff; public event ControllerInteractionEventHandler AliasGrabOn; public event ControllerInteractionEventHandler AliasGrabOff; public event ControllerInteractionEventHandler AliasUseOn; public event ControllerInteractionEventHandler AliasUseOff; public event ControllerInteractionEventHandler AliasMenuOn; public event ControllerInteractionEventHandler AliasMenuOff; private uint controllerIndex; private SteamVR_TrackedObject trackedController; private SteamVR_Controller.Device device; private Vector2 touchpadAxis = Vector2.zero; private Vector2 triggerAxis = Vector2.zero; public virtual void OnTriggerPressed(ControllerInteractionEventArgs e) { if (TriggerPressed != null) TriggerPressed(this, e); } public virtual void OnTriggerReleased(ControllerInteractionEventArgs e) { if (TriggerReleased != null) TriggerReleased(this, e); } public virtual void OnTriggerAxisChanged(ControllerInteractionEventArgs e) { if (TriggerAxisChanged != null) TriggerAxisChanged(this, e); } public virtual void OnApplicationMenuPressed(ControllerInteractionEventArgs e) { if (ApplicationMenuPressed != null) ApplicationMenuPressed(this, e); } public virtual void OnApplicationMenuReleased(ControllerInteractionEventArgs e) { if (ApplicationMenuReleased != null) ApplicationMenuReleased(this, e); } public virtual void OnGripPressed(ControllerInteractionEventArgs e) { if (GripPressed != null) GripPressed(this, e); } public virtual void OnGripReleased(ControllerInteractionEventArgs e) { if (GripReleased != null) GripReleased(this, e); } public virtual void OnTouchpadPressed(ControllerInteractionEventArgs e) { if (TouchpadPressed != null) TouchpadPressed(this, e); } public virtual void OnTouchpadReleased(ControllerInteractionEventArgs e) { if (TouchpadReleased != null) TouchpadReleased(this, e); } public virtual void OnTouchpadTouchStart(ControllerInteractionEventArgs e) { if (TouchpadTouchStart != null) TouchpadTouchStart(this, e); } public virtual void OnTouchpadTouchEnd(ControllerInteractionEventArgs e) { if (TouchpadTouchEnd != null) TouchpadTouchEnd(this, e); } public virtual void OnTouchpadAxisChanged(ControllerInteractionEventArgs e) { if (TouchpadAxisChanged != null) TouchpadAxisChanged(this, e); } public virtual void OnAliasPointerOn(ControllerInteractionEventArgs e) { if (AliasPointerOn != null) AliasPointerOn(this, e); } public virtual void OnAliasPointerOff(ControllerInteractionEventArgs e) { if (AliasPointerOff != null) AliasPointerOff(this, e); } public virtual void OnAliasGrabOn(ControllerInteractionEventArgs e) { if (AliasGrabOn != null) AliasGrabOn(this, e); } public virtual void OnAliasGrabOff(ControllerInteractionEventArgs e) { if (AliasGrabOff != null) AliasGrabOff(this, e); } public virtual void OnAliasUseOn(ControllerInteractionEventArgs e) { if (AliasUseOn != null) AliasUseOn(this, e); } public virtual void OnAliasUseOff(ControllerInteractionEventArgs e) { if (AliasUseOff != null) AliasUseOff(this, e); } public virtual void OnAliasMenuOn(ControllerInteractionEventArgs e) { if (AliasMenuOn != null) AliasMenuOn(this, e); } public virtual void OnAliasMenuOff(ControllerInteractionEventArgs e) { if (AliasMenuOff != null) AliasMenuOff(this, e); } ControllerInteractionEventArgs SetButtonEvent(ref bool buttonBool, bool value, float buttonPressure) { buttonBool = value; ControllerInteractionEventArgs e; e.controllerIndex = controllerIndex; e.buttonPressure = buttonPressure; e.touchpadAxis = device.GetAxis(); float angle = Mathf.Atan2(e.touchpadAxis.y, e.touchpadAxis.x) * Mathf.Rad2Deg; angle = 90.0f - angle; if (angle < 0) angle += 360.0f; e.touchpadAngle = angle; return e; } void Awake() { trackedController = GetComponent<SteamVR_TrackedObject>(); } void Start() { controllerIndex = (uint)trackedController.index; device = SteamVR_Controller.Input((int)controllerIndex); } void EmitAlias(ButtonAlias type, bool touchDown, float buttonPressure, ref bool buttonBool) { if (pointerToggleButton == type) { if (touchDown) { pointerPressed = true; OnAliasPointerOn(SetButtonEvent(ref buttonBool, true, buttonPressure)); } else { pointerPressed = false; OnAliasPointerOff(SetButtonEvent(ref buttonBool, false, buttonPressure)); } } if (grabToggleButton == type) { if (touchDown) { grabPressed = true; OnAliasGrabOn(SetButtonEvent(ref buttonBool, true, buttonPressure)); } else { grabPressed = false; OnAliasGrabOff(SetButtonEvent(ref buttonBool, false, buttonPressure)); } } if (useToggleButton == type) { if (touchDown) { usePressed = true; OnAliasUseOn(SetButtonEvent(ref buttonBool, true, buttonPressure)); } else { usePressed = false; OnAliasUseOff(SetButtonEvent(ref buttonBool, false, buttonPressure)); } } if (menuToggleButton == type) { if (touchDown) { menuPressed = true; OnAliasMenuOn(SetButtonEvent(ref buttonBool, true, buttonPressure)); } else { menuPressed = false; OnAliasMenuOff(SetButtonEvent(ref buttonBool, false, buttonPressure)); } } } bool Vector2ShallowEquals(Vector2 vectorA, Vector2 vectorB) { return (vectorA.x.ToString("F" + axisFidelity) == vectorB.x.ToString("F" + axisFidelity) && vectorA.y.ToString("F" + axisFidelity) == vectorB.y.ToString("F" + axisFidelity)); } void Update() { controllerIndex = (uint)trackedController.index; device = SteamVR_Controller.Input((int)controllerIndex); Vector2 currentTriggerAxis = device.GetAxis(Valve.VR.EVRButtonId.k_EButton_SteamVR_Trigger); Vector2 currentTouchpadAxis = device.GetAxis(); if (Vector2ShallowEquals(triggerAxis, currentTriggerAxis)) { triggerAxisChanged = false; } else { OnTriggerAxisChanged(SetButtonEvent(ref triggerAxisChanged, true, currentTriggerAxis.x)); } if (Vector2ShallowEquals(touchpadAxis, currentTouchpadAxis)) { touchpadAxisChanged = false; } else { OnTouchpadAxisChanged(SetButtonEvent(ref touchpadTouched, true, 1f)); touchpadAxisChanged = true; } touchpadAxis = new Vector2(currentTouchpadAxis.x, currentTouchpadAxis.y); triggerAxis = new Vector2(currentTriggerAxis.x, currentTriggerAxis.y); //Trigger if (device.GetTouchDown(SteamVR_Controller.ButtonMask.Trigger)) { OnTriggerPressed(SetButtonEvent(ref triggerPressed, true, currentTriggerAxis.x)); EmitAlias(ButtonAlias.Trigger, true, currentTriggerAxis.x, ref triggerPressed); } else if (device.GetTouchUp(SteamVR_Controller.ButtonMask.Trigger)) { OnTriggerReleased(SetButtonEvent(ref triggerPressed, false, 0f)); EmitAlias(ButtonAlias.Trigger, false, 0f, ref triggerPressed); } //ApplicationMenu if (device.GetTouchDown(SteamVR_Controller.ButtonMask.ApplicationMenu)) { OnApplicationMenuPressed(SetButtonEvent(ref applicationMenuPressed, true, 1f)); EmitAlias(ButtonAlias.Application_Menu, true, 1f, ref applicationMenuPressed); } else if (device.GetTouchUp(SteamVR_Controller.ButtonMask.ApplicationMenu)) { OnApplicationMenuReleased(SetButtonEvent(ref applicationMenuPressed, false, 0f)); EmitAlias(ButtonAlias.Application_Menu, false, 0f, ref applicationMenuPressed); } //Grip if (device.GetTouchDown(SteamVR_Controller.ButtonMask.Grip)) { OnGripPressed(SetButtonEvent(ref gripPressed, true, 1f)); EmitAlias(ButtonAlias.Grip, true, 1f, ref gripPressed); } else if (device.GetTouchUp(SteamVR_Controller.ButtonMask.Grip)) { OnGripReleased(SetButtonEvent(ref gripPressed, false, 0f)); EmitAlias(ButtonAlias.Grip, false, 0f, ref gripPressed); } //Touchpad Pressed if (device.GetPressDown(SteamVR_Controller.ButtonMask.Touchpad)) { OnTouchpadPressed(SetButtonEvent(ref touchpadPressed, true, 1f)); EmitAlias(ButtonAlias.Touchpad_Press, true, 1f, ref touchpadPressed); } else if (device.GetPressUp(SteamVR_Controller.ButtonMask.Touchpad)) { OnTouchpadReleased(SetButtonEvent(ref touchpadPressed, false, 0f)); EmitAlias(ButtonAlias.Touchpad_Press, false, 0f, ref touchpadPressed); } //Touchpad Touched if (device.GetTouchDown(SteamVR_Controller.ButtonMask.Touchpad)) { OnTouchpadTouchStart(SetButtonEvent(ref touchpadTouched, true, 1f)); EmitAlias(ButtonAlias.Touchpad_Touch, true, 1f, ref touchpadTouched); } else if (device.GetTouchUp(SteamVR_Controller.ButtonMask.Touchpad)) { OnTouchpadTouchEnd(SetButtonEvent(ref touchpadTouched, false, 0f)); EmitAlias(ButtonAlias.Touchpad_Touch, false, 0f, ref touchpadTouched); } } } }
在这个类中我们可以看到，枚举类ButtonAlias里的元素，分别对应HTCVive控制柄上的按钮：
Trigger：能扣动的那个按钮； Grip：控制柄侧面的两个按钮； Touchpad_Touch：触摸板的触控； Touchpad_Press：触摸板的按压； Application_Menu：触摸板上方的小按钮，触摸板下方的按钮是统一的总菜单功能键，不能自定义开发，所以没有与它对应的名称。（这句是我的理解，但没有试验过，如果哪位试过，望告知...）
ControllerInteractionEventHandler类型的委托方法有： TriggerPressed——扳机按下； TriggerReleased——扳机放开； TriggerAxisChanged——扳机轴值的改变； ApplicationMenuPressed——ApplicationMenu按钮按下； ApplicationMenuReleased——ApplicationMenu按钮放开； GripPressed——Grip按钮按下； GripReleased——Grip按钮放开； TouchpadPressed——触摸板按钮按下； TouchpadReleased——触摸板按钮放开； TouchpadTouchStart——触摸板开始触摸； TouchpadTouchEnd——触摸板结束触摸； TouchpadAxisChanged——触摸板触摸时的轴值变化； AliasPointerOn； AliasPointerOff； AliasGrabOn； AliasGrabOff； AliasUseOn； AliasUseOff； AliasMenuOn； AliasMenuOff；
接下来，我们来看下，Toolkit具体是怎么自己封装的SteamVR控制柄的事件的。
在VRTK_ControllerEvents.cs这个脚本的Update()中，我们先找到这样一段代码：
从这段代码中（代码的意思很简单，我就不说了，具体看下它的逻辑处理），我们可以看到，每帧监听一次SteamVR中的控制柄状态，当监听到状态后，执行一次自己的委托事件（ControllerInteractionEventHandler），并且执行一次EmitAlias(ButtonAlias type, bool touchDown, float buttonPressure, ref bool buttonBool)方法。EmitAlias方法是用来判断并分发事件给AliasXX(oN/oFF)的（就是刚才分割线以下的那些委托方法）。
至于AliasXX(oN/oFF)这些委托方法怎么用？我们可以先看下这个VRTK_ControllerEvents.cs挂接脚本在Inspector面板中的序列化属性：
AliasXX(oN/oFF)委托方法对应：
至于Inspector面板中的其它属性，都没有实际用处，不需要我们去自定义，所以如果不想看到的话，可以自己在脚本中的相应变量上加上[HideInInspector]，最后：
Tollkit对SteamVR的封装逻辑很简单，用这么长的篇幅来说，主要目的还是想自己再仔细研究下，虽然它的逻辑简单，但是我觉的它的代码结构很漂亮。不感兴趣的，可以忽略。至于怎么用，Toolkit也给出了一个挂接脚本，很简单的用法，我挂一下它的代码就行，看完很容易理解：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 using UnityEngine; using System.Collections; using VRTK; public class VRTK_ControllerEvents_ListenerExample : MonoBehaviour { // Use this for initialization void Start () { if (GetComponent<VRTK_ControllerEvents>() == null) { Debug.LogError("VRTK_ControllerEvents_ListenerExample is required to be attached to a SteamVR Controller that has the VRTK_ControllerEvents script attached to it"); return; } //Setup controller event listeners GetComponent<VRTK_ControllerEvents>().TriggerPressed += new ControllerInteractionEventHandler(DoTriggerPressed); GetComponent<VRTK_ControllerEvents>().TriggerReleased += new ControllerInteractionEventHandler(DoTriggerReleased); GetComponent<VRTK_ControllerEvents>().TriggerAxisChanged += new ControllerInteractionEventHandler(DoTriggerAxisChanged); GetComponent<VRTK_ControllerEvents>().ApplicationMenuPressed += new ControllerInteractionEventHandler(DoApplicationMenuPressed); GetComponent<VRTK_ControllerEvents>().ApplicationMenuReleased += new ControllerInteractionEventHandler(DoApplicationMenuReleased); GetComponent<VRTK_ControllerEvents>().GripPressed += new ControllerInteractionEventHandler(DoGripPressed); GetComponent<VRTK_ControllerEvents>().GripReleased += new ControllerInteractionEventHandler(DoGripReleased); GetComponent<VRTK_ControllerEvents>().TouchpadPressed += new ControllerInteractionEventHandler(DoTouchpadPressed); GetComponent<VRTK_ControllerEvents>().TouchpadReleased += new ControllerInteractionEventHandler(DoTouchpadReleased); GetComponent<VRTK_ControllerEvents>().TouchpadTouchStart += new ControllerInteractionEventHandler(DoTouchpadTouchStart); GetComponent<VRTK_ControllerEvents>().TouchpadTouchEnd += new ControllerInteractionEventHandler(DoTouchpadTouchEnd); GetComponent<VRTK_ControllerEvents>().TouchpadAxisChanged += new ControllerInteractionEventHandler(DoTouchpadAxisChanged); } void DebugLogger(uint index, string button, string action, ControllerInteractionEventArgs e) { Debug.Log("Controller on index '" + index + "' " + button + " has been " + action + " with a pressure of " + e.buttonPressure + " / trackpad axis at: " + e.touchpadAxis + " (" + e.touchpadAngle + " degrees)"); } void DoTriggerPressed(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "TRIGGER", "pressed down", e); } void DoTriggerReleased(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "TRIGGER", "released", e); } void DoTriggerAxisChanged(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "TRIGGER", "axis changed", e); } void DoApplicationMenuPressed(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "APPLICATION MENU", "pressed down", e); } void DoApplicationMenuReleased(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "APPLICATION MENU", "released", e); } void DoGripPressed(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "GRIP", "pressed down", e); } void DoGripReleased(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "GRIP", "released", e); } void DoTouchpadPressed(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "TOUCHPAD", "pressed down", e); } void DoTouchpadReleased(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "TOUCHPAD", "released", e); } void DoTouchpadTouchStart(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "TOUCHPAD", "touched", e); } void DoTouchpadTouchEnd(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "TOUCHPAD", "untouched", e); } void DoTouchpadAxisChanged(object sender, ControllerInteractionEventArgs e) { DebugLogger(e.controllerIndex, "TOUCHPAD", "axis changed", e); } }
