PannerNode.orientationX

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orientationX 特性为 PannerNode interface indicates the X (horizontal) component of the direction in which the audio source is facing, in a 3D Cartesian coordinate space.

The complete vector is defined by the position of the audio source, given as ( positionX , positionY , positionZ ), and the orientation of the audio source (that is, the direction in which it's facing), given as ( orientationX , orientationY , orientationZ ).

Depending on the directionality of the sound (as specified using the attributes coneInnerAngle , coneOuterAngle ，和 coneOuterGain ), the orientation of the sound may alter the perceived volume of the sound as it's being played. If the sound is pointing toward the listener, it will be louder than if the sound is pointed away from the listener.

AudioParam contained by this property is read only; however, you can still change the value of the parameter by assigning a new value to its AudioParam.value 特性。

句法

var orientationX = PannerNode.orientationX;
PannerNode.orientationX.value = newOrientationX;

值

AudioParam whose value is the X component of the direction in which the audio source is facing, in 3D Cartesian coordinate space.

范例

In this example, we'll demonstrate how changing the orientation parameters of a PannerNode in combination with coneInnerAngle and coneOuterAngle affects volume. To help us visualise how the orientation vector affects, we can use the Right-hand rule :

This chart visualises how the PannerNode orientation vectors affect the direction of the sound cone.

First, let's start by writing a utility function to figure out our orientation vector. The X and Z components are always at a 90° to each other, so we can use the sine and cosine functions, which are offset by the same amount in radians. However, normally this would mean the PannerNode points to the left of the listener at 0° rotation – since `x = cos(0) = 1` and `z = sin(0) = 0`. It's more useful to offset the angle by -90°, which means the PannerNode will point directly at the listener at 0° rotation.

// this utility converts amount of rotation around the Y axis
// (i.e. rotation in the 'horizontal plane') to an orientation vector
const yRotationToVector = degrees => {
  // convert degrees to radians and offset the angle so 0 points towards the listener
  const radians = (degrees - 90) * (Math.PI / 180);
  // using cosine and sine here ensures the output values are always normalised
  // i.e. they range between -1 and 1
  const x = Math.cos(radians);
  const z = Math.sin(radians);
  // we hard-code the Y component to 0, as Y is the axis of rotation
  return [x, 0, z];
};

Now we can create our AudioContext , an oscillator and a PannerNode :

const context = new AudioContext();
const osc = new OscillatorNode(context);
osc.type = 'sawtooth';
const panner = new PannerNode(context);
panner.panningModel = 'HRTF';

Next, we set up the cone of our spatialised sound, determining the area in which it can be heard:

// this value determines the size of the area in which the sound volume is constant
// if coneInnerAngle == 30, it means that when the sound is rotated
// by at most 15 (30/2) degrees either direction, the volume won't change
panner.coneInnerAngle = 30;
// this value determines the size of the area in which the sound volume decreases gradually
// if coneOuterAngle == 45 and coneInnerAngle == 30, it means that when the sound is rotated
// by between 15 (30/2) and 22.5 (45/2) degrees either direction,
// the volume will decrease gradually
panner.coneOuterAngle = 45;
// this value determines the volume of the sound outside of both inner and outer cone
// setting it to 0 means there is no sound, so we can clearly hear when we leave the cone
// 0 is also the default
panner.coneOuterGain = 0;
// increase the Z position to ensure the cone has an effect
// (otherwise the sound is located at the same position as the listener)
panner.positionZ.setValueAtTime(1, context.currentTime);

Having set up the PannerNode , we can now schedule some updates to its Y-axis rotation:

// calculate the vector for no rotation
// this means the sound will play at full volume
const [x1, y1, z1] = yRotationToVector(0);
// schedule the no-rotation vector immediately
panner.orientationX.setValueAtTime(x1, context.currentTime);
panner.orientationY.setValueAtTime(y1, context.currentTime);
panner.orientationZ.setValueAtTime(z1, context.currentTime);
// calculate the vector for -22.4 degrees
// since our coneOuterAngle is 45, this will just about make the sound audible
// if we set it to +/-22.5, the sound volume will be 0, as the threshold is exclusive
const [x2, y2, z2] = yRotationToVector(-22.4);
panner.orientationX.setValueAtTime(x2, context.currentTime + 2);
panner.orientationY.setValueAtTime(y2, context.currentTime + 2);
panner.orientationZ.setValueAtTime(z2, context.currentTime + 2);

Finally, let's connect all our nodes and start the oscillator!

osc.connect(panner)
   .connect(context.destination);
osc.start(0);

规范

规范	状态	注释
Web 音频 API The definition of 'orientationX' in that specification.	工作草案

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`orientationX`	Chrome Yes	Edge ≤18	Firefox 50	IE 不支持 No	Opera Yes	Safari 不支持 No	WebView Android Yes	Chrome Android Yes	Firefox Android 50	Opera Android Yes	Safari iOS 不支持 No	Samsung Internet Android Yes

图例

完整支持
不支持

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元数据

最后修改： 2020 年 1 月 22 日

Web 音频 API
PannerNode
构造函数
1. PannerNode()
特性
1. coneInnerAngle
2. coneOuterAngle
3. coneOuterGain
4. distanceModel
5. maxDistance
6. orientationX
7. orientationY
8. orientationZ
9. panningModel
10. positionX
11. positionY
12. positionZ
13. refDistance
14. rolloffFactor
方法
继承：
1. AudioNode
2. EventTarget
Related pages for Web Audio API

在此页

句法

值

范例

规范

浏览器兼容性

图例

另请参阅

相关话题