Mobile Input 移動設(shè)備輸入

On iOS and Android, the Input class offers access to touchscreen, accelerometer and geographical/location input.

在 iOS/Android Input類提供觸摸屏、加速度計和地理/位置輸入。

Access to keyboard on mobile devices is provided via the iOS keyboard.

訪問鍵盤是通過iOS keyboard。

Multi-Touch Screen 多點觸控屏幕

The iPhone and iPod Touch devices are capable of tracking up to five fingers touching the screen simultaneously. You can retrieve the status of each finger touching the screen during the last frame by accessing the Input.touches property array.

iPhone和iPod觸控設(shè)備是具有五個手指觸控屏幕同時跟蹤能力。通過訪問Input.touches屬性數(shù)值，可以取回每個手指觸摸屏幕在最后一幀的狀態(tài)。

Each finger touch is represented by an Input.Touch data structure:

每個手指觸控是通過Input.touches數(shù)據(jù)結(jié)構(gòu)描述的：

• fingerId 手指索引
  The unique index for a touch. 觸摸的唯一索引。
• position 位置
  The screen position of the touch. 觸摸屏幕的位置。
• deltaPosition 增量位置
  The screen position change since the last frame.
  自最后一幀改變的屏幕位置。
• deltaTime 增量時間
  Amount of time that has passed since the last state change.
  從最后狀態(tài)改變到現(xiàn)在經(jīng)過的時間
• tapCount 點擊數(shù)
  The iPhone/iPad screen is able to distinguish quick finger taps by the user. This counter will let you know how many times the user has tapped the screen without moving a finger to the sides. Android devices do not count number of taps, this field is always 1.
  iPhone/iPad屏幕能夠識別用過的快速點擊， 這個計數(shù)器讓你知道用戶點擊屏幕多少次，而不是移動手指。android設(shè)備不對點擊計數(shù)，這個方法總是返回1
• phase 相位（狀態(tài)）
  Describes so called "phase" or the state of the touch. It can help you determine if the touch just began, if user moved the finger or if he just lifted the finger.
  描述觸摸的狀態(tài)，可以幫助開發(fā)者確定用戶是否剛開始觸摸，是否用戶移動手指，是否用戶剛剛抬起手指。

Phase can be one of the following:

相位（狀態(tài)）可能是下列之一：

• Began 開始
  A finger just touched the screen. 手指剛剛觸摸屏幕
• Moved 移動
  A finger moved on the screen. 手指在屏幕上移動
• Stationary 靜止
  A finger is touching the screen but hasn't moved since the last frame.
  手指觸摸屏幕，但是自最后一幀沒有移動
• Ended 結(jié)束
  A finger was lifted from the screen. This is the final phase of a touch.
  手指從屏幕上抬起，這是觸控的最后狀態(tài)。
• Canceled 取消
  The system cancelled tracking for the touch, as when (for example) the user puts the device to her face or more than five touches happened simultaneously. This is the final phase of a touch.
  系統(tǒng)取消了觸控跟蹤，如，用戶將設(shè)備放在了臉上或超過同時超過5個觸摸點。這是觸控的最后狀態(tài)。

Following is an example script which will shoot a ray whenever the user taps on the screen:

下面的例子，只要用戶在屏幕上點擊，將射出一條光線：

var particle : GameObject;
function Update () {
	for (var touch : Touch in Input.touches) {
		if (touch.phase == TouchPhase.Began) {
			// Construct a ray from the current touch coordinates
			//從當(dāng)前的觸摸坐標(biāo)建一條光線
			var ray = Camera.main.ScreenPointToRay (touch.position);
			if (Physics.Raycast (ray)) {
				// Create a particle if hit
				//如果觸摸就創(chuàng)建一個例子
				Instantiate (particle, transform.position, transform.rotation);
			}
		}
	}
}

Mouse Simulation 鼠標(biāo)模擬

On top of native touch support Unity iOS/Android provides a mouse simulation. You can use mouse functionality from the standard Input class.

除了原有的觸控之外，Unity iOS/Android還提供了鼠標(biāo)模擬。從標(biāo)準(zhǔn)的Input類中，可以使用鼠標(biāo)功能。

Accelerometer 加速度傳感器

As the mobile device moves, a built-in accelerometer reports linear acceleration changes along the three primary axes in three-dimensional space. Acceleration along each axis is reported directly by the hardware as G-force values. A value of 1.0 represents a load of about +1g along a given axis while a value of -1.0 represents -1g. If you hold the device upright (with the home button at the bottom) in front of you, the X axis is positive along the right, the Y axis is positive directly up, and the Z axis is positive pointing toward you.

在手機設(shè)備移動時，內(nèi)置加速度傳感器報告在三維空間，沿著三個主要軸上的線性加速度改變。沿著每個軸的加速度由硬件作為G-force值直接報告。值為1表示沿給定軸增加1g負(fù)載，值為-1.0表示減少1g。如果用戶在面前豎直拿著設(shè)備（home按鈕在底部），X軸指向右，Y軸指向上，Z軸指向前。

You can retrieve the accelerometer value by accessing the Input.acceleration property.

可以通過訪問Input.acceleration屬性，取回加速度傳感器的值。

The following is an example script which will move an object using the accelerometer:

下面的例子，將使用加速度傳感器移動一個物體：

var speed = 10.0;
function Update () {
	var dir : Vector3 = Vector3.zero;

	// we assume that the device is held parallel to the ground
	// and the Home button is in the right hand
	//假設(shè)該設(shè)備與地面平行，Home按鈕在右邊
	// remap the device acceleration axis to game coordinates:
	//重新映射設(shè)備加速度軸到游戲坐標(biāo)：
	//  1) XY plane of the device is mapped onto XZ plane
	//		設(shè)備的XY平面映射到XZ平面
	//  2) rotated 90 degrees around Y axis
	//		沿著Y軸旋轉(zhuǎn)90度
	dir.x = -Input.acceleration.y;
	dir.z = Input.acceleration.x;

	// clamp acceleration vector to the unit sphere
	//鉗制加速度向量到單位球
	if (dir.sqrMagnitude > 1)
		dir.Normalize();

	// Make it move 10 meters per second instead of 10 meters per frame...
	//使它每秒移動10米，而不是每幀10米
	dir *= Time.deltaTime;

	// Move object 移動物體
	transform.Translate (dir * speed);
}

Low-Pass Filter 低通過濾器

Accelerometer readings can be jerky and noisy. Applying low-pass filtering on the signal allows you to smooth it and get rid of high frequency noise.

加速度傳感器數(shù)值可能被顛簸和噪音影響。應(yīng)用低通過濾器在信號上可以是它平滑，并擺脫高頻噪音的干擾。

The following script shows you how to apply low-pass filtering to accelerometer readings:

下面的例子顯示，怎樣應(yīng)用低通到加速度傳感器數(shù)值：

var AccelerometerUpdateInterval : float = 1.0 / 60.0;
var LowPassKernelWidthInSeconds : float = 1.0;

private var LowPassFilterFactor : float = AccelerometerUpdateInterval / LowPassKernelWidthInSeconds; // tweakable
private var lowPassValue : Vector3 = Vector3.zero;
function Start () {
	lowPassValue = Input.acceleration;
}

function LowPassFilterAccelerometer() : Vector3 {
	lowPassValue = Mathf.Lerp(lowPassValue, Input.acceleration, LowPassFilterFactor);
	return lowPassValue;
}

The greater the value of LowPassKernelWidthInSeconds, the slower the filtered value will converge towards the current input sample (and vice versa). You should be able to use the LowPassFilter() function instead of avgSamples().

LowPassKernelWidthInSeconds的值越大， 被過濾值將匯集當(dāng)前輸入采樣越慢，反之亦然。應(yīng)該使用LowPassFilter（）函數(shù)，而不是avgSamples（）。

I'd like as much precision as possible when reading the accelerometer. What should I do?
我想盡可能的讀取加速度傳感器的更高精度，應(yīng)該怎樣做呢？

Reading the Input.acceleration variable does not equal sampling the hardware. Put simply, Unity samples the hardware at a frequency of 60Hz and stores the result into the variable. In reality, things are a little bit more complicated -- accelerometer sampling doesn't occur at consistent time intervals, if under significant CPU loads. As a result, the system might report 2 samples during one frame, then 1 sample during the next frame.

讀取 Input.acceleration變量，不等于從硬件采樣。簡而言之，Unity硬件樣品頻率為60Hz并儲存結(jié)果到變量。在現(xiàn)實中，是一個有點復(fù)雜的東西--加速度傳感器采樣不會發(fā)生在一致的時間間隔，如果大量的CPU負(fù)荷的情況下，因此，系統(tǒng)可能會報告一幀中的2個采樣，那么1個采樣在下一幀。

You can access all measurements executed by accelerometer during the frame. The following code will illustrate a simple average of all the accelerometer events that were collected within the last frame:

通過加速度傳感器在幀間可以訪問所有測量。

var period : float = 0.0;
var acc : Vector3 = Vector3.zero;
for (var evnt : iPhoneAccelerationEvent  in iPhoneInput.accelerationEvents) {
	acc += evnt.acceleration * evnt.deltaTime;
	period += evnt.deltaTime;
}
if (period > 0)
	acc *= 1.0/period;
return acc;

Further Reading 深入閱讀

The Unity mobile input API is originally based on Apple's API. It may help to learn more about the native API to better understand Unity's Input API. You can find the Apple input API documentation here:

Unity移動Input API本來是基于Apple's API。這可以幫助你學(xué)習(xí)更多關(guān)于原生API，更好的理解Untiy的Input API。在這里找到Apple的 Input API文檔：

• Programming Guide: Event Handling (Apple iPhone SDK documentation)
• UITouch Class Reference (Apple iOS SDK documentation)

Note: The above links reference your locally installed iPhone SDK Reference Documentation and will contain native ObjectiveC code. It is not necessary to understand these documents for using Unity on mobile devices, but may be helpful to some!

注意：上面的鏈接參考你本地安裝的iPHone SDK參考文檔，也將包含ObjectiveC代碼。對于在移動設(shè)備使用Unity開發(fā)，沒有必要理解這些文檔，但是可能或許有些一下幫助。

頁面最近更新：2013-04-26