BaseAudioContext: createPanner() method
The createPanner()
method of the BaseAudioContext
Interface is used to create a new PannerNode
, which is used to
spatialize an incoming audio stream in 3D space.
The panner node is spatialized in relation to the AudioContext's
AudioListener
(defined by the AudioContext.listener
attribute), which represents the position and orientation of the person listening to the
audio.
Note: The PannerNode()
constructor is the recommended way to create a PannerNode
; see
Creating an AudioNode.
Syntax
js
createPanner()
Parameters
None.
Return value
A PannerNode
.
Examples
In the following example, you can see an example of how the createPanner()
method, AudioListener
and PannerNode
would be used to
control audio spatialization. Generally you will define the position in 3D space that
your audio listener and panner (source) occupy initially, and then update the position
of one or both of these as the application is used. You might be moving a character
around inside a game world for example, and wanting delivery of audio to change
realistically as your character moves closer to or further away from a music player such
as a stereo. In the example you can see this being controlled by the functions
moveRight()
, moveLeft()
, etc., which set new values for the
panner position via the PositionPanner()
function.
To see a complete implementation, check out our panner-node example (view the source code) — this demo transports you to the 2.5D "Room of metal", where you can play a track on a boom box and then walk around the boom box to see how the sound changes!
Note how we have used some feature detection to either give the browser the newer
property values (like AudioListener.forwardX
) for setting position, etc.
if it supports those, or older methods (like
AudioListener.setOrientation()
) if it still supports those but not the
new properties.
js
// set up listener and panner position information
const WIDTH = window.innerWidth;
const HEIGHT = window.innerHeight;
const xPos = Math.floor(WIDTH / 2);
const yPos = Math.floor(HEIGHT / 2);
const zPos = 295;
// define other variables
const audioCtx = new AudioContext();
const panner = audioCtx.createPanner();
panner.panningModel = "HRTF";
panner.distanceModel = "inverse";
panner.refDistance = 1;
panner.maxDistance = 10000;
panner.rolloffFactor = 1;
panner.coneInnerAngle = 360;
panner.coneOuterAngle = 0;
panner.coneOuterGain = 0;
if (panner.orientationX) {
panner.orientationX.setValueAtTime(1, audioCtx.currentTime);
panner.orientationY.setValueAtTime(0, audioCtx.currentTime);
panner.orientationZ.setValueAtTime(0, audioCtx.currentTime);
} else {
panner.setOrientation(1, 0, 0);
}
const listener = audioCtx.listener;
if (listener.forwardX) {
listener.forwardX.setValueAtTime(0, audioCtx.currentTime);
listener.forwardY.setValueAtTime(0, audioCtx.currentTime);
listener.forwardZ.setValueAtTime(-1, audioCtx.currentTime);
listener.upX.setValueAtTime(0, audioCtx.currentTime);
listener.upY.setValueAtTime(1, audioCtx.currentTime);
listener.upZ.setValueAtTime(0, audioCtx.currentTime);
} else {
listener.setOrientation(0, 0, -1, 0, 1, 0);
}
let source;
const play = document.querySelector(".play");
const stop = document.querySelector(".stop");
const boomBox = document.querySelector(".boom-box");
const listenerData = document.querySelector(".listener-data");
const pannerData = document.querySelector(".panner-data");
leftBound = -xPos + 50;
rightBound = xPos - 50;
xIterator = WIDTH / 150;
// listener will always be in the same place for this demo
if (listener.positionX) {
listener.positionX.setValueAtTime(xPos, audioCtx.currentTime);
listener.positionY.setValueAtTime(yPos, audioCtx.currentTime);
listener.positionZ.setValueAtTime(300, audioCtx.currentTime);
} else {
listener.setPosition(xPos, yPos, 300);
}
listenerData.textContent = `Listener data: X ${xPos} Y ${yPos} Z 300`;
// panner will move as the boombox graphic moves around on the screen
function positionPanner() {
if (panner.positionX) {
panner.positionX.setValueAtTime(xPos, audioCtx.currentTime);
panner.positionY.setValueAtTime(yPos, audioCtx.currentTime);
panner.positionZ.setValueAtTime(zPos, audioCtx.currentTime);
} else {
panner.setPosition(xPos, yPos, zPos);
}
pannerData.textContent = `Panner data: X ${xPos} Y ${yPos} Z ${zPos}`;
}
Note: In terms of working out what position values to apply to the listener and panner, to make the sound appropriate to what the visuals are doing on screen, there is quite a bit of math involved, but you will soon get used to it with a bit of experimentation.
Specifications
Specification |
---|
Web Audio API # dom-baseaudiocontext-createpanner |
Browser compatibility
BCD tables only load in the browser