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webvr_en.html
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webvr_en.html
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<!doctype html>
<html lang="en">
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<title>WebVR</title>
<style>
@media print {
html { margin: 0 !important; }
body { font-family: serif; }
th, td { font-family: inherit; }
a { color: inherit !important; }
.example:before { font-family: serif !important; }
a:link, a:visited { text-decoration: none !important; }
a:link:after, a:visited:after { /* create a cross-ref "see..." */; }
}
@page {
margin: 1.5cm 1.1cm;
}
h1, h2, h3, h4, h5, h6 { page-break-after: avoid; }
figure, div.figure, div.sidefigure, pre, table.propdef, table.propdef-extra,
.example { page-break-inside: avoid; }
dt { page-break-after: avoid; }
body {
background: white;
/* background-image: floating-margin-image-goes-here; */
background-position: top left;
background-attachment: fixed;
background-repeat: no-repeat;
color: black;
counter-reset: exampleno figure issue;
font-family: sans-serif;
line-height: 1.5;
margin: 0 auto;
max-width: 50em;
padding: 2em 1em 2em 70px;
}
/* General structural markup */
h1, h2, h3, h4, h5, h6 { text-align: left; }
h1, h2, h3 { color: #005A9C; }
h1 { font: 170% sans-serif; }
h2 { font: 140% sans-serif; }
h3 { font: 120% sans-serif; }
h4 { font: bold 100% sans-serif; }
h5 { font: italic 100% sans-serif; }
h6 { font: small-caps 100% sans-serif; }
h2, h3, h4, h5, h6 { margin-top: 3em; }
h1 + h2 { margin-top: 0em; }
h2 + h3, h3 + h4, h4 + h5, h5 + h6 { margin-top: 1.2em; }
.head { margin-bottom: 1em; }
.head h1 { margin-top: 2em; clear: both; }
.head table { margin-left: 2em; margin-top: 2em; }
.head dd { margin-bottom: 0; }
p.copyright { font-size: small; }
p.copyright small { font-size: small; }
pre { margin: 1em 0 1em 2em; overflow: auto; }
pre, code, .idl-code {
font-size: .9em;
font-family: Menlo, Consolas, "DejaVu Sans Mono", monospace;
}
pre .idl-code, pre code { font-size: 1em; }
dt dfn code { font-size: inherit; }
dfn { font-weight: bolder; }
dfn var { font-style: normal; }
s, del {text-decoration: line-through; color: red; }
u, ins {text-decoration: underline; background: #bfa; }
sup {
vertical-align: super;
font-size: 80%
}
details { display: block; }
dt { font-weight: bold; }
dd { margin: 0 0 1em 2em; }
ul, ol { margin-left: 0; padding-left: 2em; }
li { margin: 0.25em 2em 0.5em 0; padding-left: 0; }
[data-md] > :first-child { margin-top: 0; }
[data-md] > :last-child { margin-bottom: 0; }
td.pre {
white-space: pre-wrap;
}
.css, .property { color: #005a9c; }
.property { white-space: nowrap; }
/* Boilerplate sections */
ul.indexlist { margin-left: 0; columns: 13em; }
ul.indexlist li { margin-left: 0; list-style: none }
ul.indexlist li li { margin-left: 1em; }
ul.indexlist a { font-weight: bold; }
ul.indexlist ul, ul.indexlist dl { font-size: smaller; }
ul.indexlist dl { margin-top: 0; }
ul.indexlist dt { margin: .2em 0 .2em 20px; }
ul.indexlist dd { margin: .2em 0 .2em 40px; }
.toc {
font-weight: bold;
line-height: 1.3;
list-style: none;
margin: 1em 0 0 5em;
padding: 0;
}
.toc ul { margin: 0; padding: 0; font-weight: normal; }
.toc ul ul { margin: 0 0 0 2em; font-style: italic; }
.toc ul ul ul { margin: 0}
.toc > li { margin: 1.5em 0; padding: 0; }
.toc li { clear: both; }
.toc ul.toc li { margin: 0.3em 0 0 0; }
.toc a { border-bottom-style: none; }
.toc a:hover, ul.toc a:focus { border-bottom-style: solid; }
/* Section numbers in a column of their own */
.toc span.secno {float: left; width: 4em; margin-left: -5em}
.toc ul ul span.secno { margin-left: -7em; }
table.proptable {
font-size: small;
border-collapse: collapse;
border-spacing: 0;
text-align: left;
margin: 1em 0;
}
table.proptable td, table.proptable th {
padding: 0.4em;
text-align: center;
}
table.proptable tr:hover td { background: #DEF; }
/* Links */
a[href] { color: inherit; border-bottom: 1px solid silver; text-decoration: none; }
a[href]:hover { background: #ffa; }
a[href]:active { color: #C00; background: transparent; }
img, a.logo { border-style: none; }
.heading, .issue, .note, .example, li, dt { position: relative; }
/* CSS-ish link types */
[data-link-type="property"]::before,
[data-link-type="propdesc"]::before,
[data-link-type="descriptor"]::before,
[data-link-type="value"]::before,
[data-link-type="function"]::before,
[data-link-type="at-rule"]::before,
[data-link-type="selector"]::before,
[data-link-type="maybe"]::before {content: "“";}
[data-link-type="property"]::after,
[data-link-type="propdesc"]::after,
[data-link-type="descriptor"]::after,
[data-link-type="value"]::after,
[data-link-type="function"]::after,
[data-link-type="at-rule"]::after,
[data-link-type="selector"]::after,
[data-link-type="maybe"]::after {content: "”";}
[data-link-type].production::before,
[data-link-type].production::after,
.prod [data-link-type]::before,
.prod [data-link-type]::after { content: ""; }
/* Element-type link styling */
[data-link-type=element] { font-family: monospace; }
[data-link-type=element]::before { content: "<" }
[data-link-type=element]::after { content: ">" }
/* Self-links */
a.self-link {
position: absolute;
top: 0;
left: -2.5em;
width: 2em;
height: 2em;
text-align: center;
border: none;
transition: opacity .2s;
opacity: .5;
}
a.self-link:hover {
opacity: 1;
}
.heading > a.self-link {
font-size: 83%;
}
li > a.self-link {
left: -3.5em;
}
dfn > a.self-link {
top: auto;
left: auto;
opacity: 0;
width: 1.5em;
height: 1.5em;
background: gray;
color: white;
font-style: normal;
transition: opacity .2s, background-color .2s, color .2s;
}
dfn:hover > a.self-link {
opacity: 1;
}
dfn > a.self-link:hover {
color: black;
}
a.self-link::before { content: "¶"; }
.heading > a.self-link::before { content: "§"; }
dfn > a.self-link::before { content: "#"; }
/* Figures */
figure {
display: block;
text-align: center;
margin: 2.5em 0;
}
figure.sidefigure {
float: right;
width: 50%;
margin: 0 0 0.5em 0.5em
}
figure pre {
text-align: left;
display: table;
margin: 1em auto;
}
figure table {
margin: auto;
}
figure img, figure object {
display: block;
margin: auto;
max-width: 100%
}
figcaption {
counter-increment: figure;
font-size: 90%;
font-style: italic;
text-align: center;
}
figcaption::before {
content: "Figure " counter(figure) ". ";
font-weight: bold;
}
dd figure { margin-left: -2em; }
/* Definition tables */
table.definition {
border-spacing: 0;
padding: 0 1em 0.5em;
width: 100%;
table-layout: fixed;
margin: 1.2em 0;
}
table.definition td, table.definition th {
padding: 0.5em;
vertical-align: baseline;
border-bottom: 1px solid #bbd7e9;
}
table.definition th:first-child {
font-style: italic;
font-weight: normal;
text-align: left;
width: 8.3em;
padding-left: 1em;
}
table.definition > tbody > tr:last-child > th,
table.definition > tbody > tr:last-child > td {
border-bottom: none;
}
table.definition tr:first-child > th,
table.definition tr:first-child > td {
padding-top: 1em;
}
/* Footnotes at the bottom of a definition table */
table.definition td.footnote {
font-style: normal;
padding-top: .6em;
width: auto;
}
table.definition td.footnote::before {
content: " ";
display: block;
height: 0.6em;
width: 4em;
border-top: thin solid;
}
/* IDL fragments */
pre.idl {
padding: .5em 1em;
margin: 1.2em 0;
}
pre.idl :link, pre.idl :visited {
color:inherit;
background:transparent;
}
/* Data tables */
/* Comes in plain, long, complex, or define varieties */
.data {
margin: 1em auto;
border-collapse: collapse;
width: 100%;
border: hidden;
}
.data {
text-align: center;
width: auto;
}
.data caption {
width: 100%;
}
.data td, .data th {
padding: 0.5em;
border-width: 1px;
border-color: silver;
border-top-style: solid;
}
.data thead td:empty {
padding: 0;
border: 0;
}
.data thead th[scope="row"] {
text-align: right;
color: inherit;
}
.data thead,
.data tbody {
color: inherit;
border-bottom: 2px solid;
}
.data colgroup {
border-left: 2px solid;
}
.data tbody th:first-child,
.data tbody td[scope="row"]:first-child {
text-align: right;
color: inherit;
border-right: 2px solid;
border-top: 1px solid silver;
padding-right: 1em;
}
.data.define td:last-child {
text-align: left;
}
.data tbody th[rowspan],
.data tbody td[rowspan] {
border-left: 1px solid silver;
}
.data tbody th[rowspan]:first-child,
.data tbody td[rowspan]:first-child {
border-left: 0;
border-right: 1px solid silver;
}
.data.complex th,
.data.complex td {
border: 1px solid silver;
}
.data td.long {
vertical-align: baseline;
text-align: left;
}
.data img {
vertical-align: middle;
}
/* Switch/case <dl>s */
dl.switch {
padding-left: 2em;
}
dl.switch > dt {
text-indent: -1.5em;
}
dl.switch > dt:before {
content: '↪';
padding: 0 0.5em 0 0;
display: inline-block;
width: 1em;
text-align: right;
line-height: 0.5em;
}
/* Style for At Risk features (intended as editorial aid, not intended for publishing) */
.atrisk::before {
position: absolute;
margin-left: -5em;
margin-top: -2px;
padding: 4px;
border: 1px solid;
content: 'At risk';
font-size: small;
background-color: white;
color: gray;
border-radius: 1em;
text-align: center;
}
/* Obsoletion notice */
details.annoying-warning[open] {
background: #fdd;
color: red;
font-weight: bold;
text-align: center;
padding: .5em;
border: thick solid red;
border-radius: 1em;
position: fixed;
left: 1em;
right: 1em;
bottom: 1em;
z-index: 1000;
}
details.annoying-warning:not([open]) > summary {
background: #fdd;
color: red;
font-weight: bold;
text-align: center;
padding: .5em;
}
/* Examples */
.example {
counter-increment: exampleno;
}
.example::before {
content: "Example";
content: "Example " counter(exampleno);
min-width: 7.5em;
text-transform: uppercase;
display: block;
}
.illegal-example::before {
content: "Invalid Example";
content: "Invalid Example" counter(exampleno);
}
.example, .illegal-example, .html, .illegal-html, .xml, .illegal-xml {
padding: 0.5em;
margin: 1em 0;
position: relative;
clear: both;
}
pre.example, pre.illegal-example, pre.html,
pre.illegal-html, pre.xml, pre.illegal-xml {
padding-top: 1.5em;
}
.illegal-example { color: red; }
.illegal-example p { color: black; }
.html { color: #600; }
.illegal-html { color: red; }
.illegal-html p { color: black; }
.xml { color: #600; }
.illegal-xml { color: red; }
.illegal-xml p { color: black; }
code.css { font-family: inherit; font-size: 100% }
code.html { color: #600 } /* inline HTML */
code.xml { color: #600 } /* inline XML */
/* Issues */
.issue {
border-color: #E05252;
background: #FBE9E9;
counter-increment: issue;
}
.issue:before {
content: "Issue " counter(issue);
padding-right: 1em;
text-transform: uppercase;
color: #E05252;
}
/* Whys */
details.why > summary {
font-style: italic;
}
details.why[open] > summary {
border-bottom: 1px silver solid;
}
/* All the blocks get similarly styled */
table.definition, pre.idl, .example, .note, details.why, .issue {
border: none;
border-left: .5em solid black;
border-left: .5rem solid black;
}
.issue, .note, .example, .why {
padding: .5em;
margin-top: 1em;
margin-bottom: 1em;
}
table.definition, pre.idl {
background: hsl(210, 70%, 95%);
border-color: hsl(210, 80%, 75%);
}
.example {
background: hsl(50, 70%, 95%);
border-color: hsl(50, 70%, 60%);
}
.example::before {
color: hsl(50, 70%, 60%);
}
.note, details.why {
background: hsl(120, 70%, 95%);
border-color: hsl(120, 70%, 60%);
}
.note::before {
color: hsl(120, 70%, 60%);
}
.issue {
background: hsl(0, 70%, 95%);
border-color: hsl(0, 70%, 60%);
}
.issue::before {
color: hsl(0, 70%, 60%);
}
span.issue, span.note {
padding: .1em .5em .15em;
border-right-width: .5em;
border-right-style: solid;
}
</style>
<meta content="Bikeshed 1.0.0" name="generator">
</head>
<body class="h-entry">
<div class="head">
<p data-fill-with="logo"></p>
<h1 class="p-name no-ref" id="title">WebVR</h1>
<h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Editor’s Draft,
<time class="dt-updated" datetime="2015-05-14">14 May 2015</time></span></h2>
<div data-fill-with="spec-metadata">
<dl>
<dt>This version:
<dd><a class="u-url" href="https://github.com/MozVR/webvr-spec/blob/master/webvr.html">https://github.com/MozVR/webvr-spec/blob/master/webvr.html</a>
<dt>Feedback:
<dd><span><a href="mailto:[email protected]?subject=%5Bwebvr%5D%20feedback">[email protected]</a> with subject line “<kbd>[webvr] <var>… message topic …</var></kbd>” (<a href="https://mail.mozilla.org/pipermail/web-vr-discuss/" rel="discussion">archives</a>)</span>
<dt class="editor">Editors:
<dd class="editor p-author h-card vcard"><a class="p-name fn u-email email" href="mailto:[email protected]">Vladimir Vukicevic</a> (<a class="p-org org" href="http:https://mozilla.com/">Mozilla</a>)
<dd class="editor p-author h-card vcard"><a class="p-name fn u-email email" href="mailto:[email protected]">Brandon Jones</a> (<a class="p-org org" href="http:https://google.com/">Google</a>)
</dl>
</div>
<div data-fill-with="warning"></div>
<p class="copyright" data-fill-with="copyright"><a href="http:https://creativecommons.org/publicdomain/zero/1.0/" rel="license"><img alt="CC0" src="https://licensebuttons.net/p/zero/1.0/80x15.png"></a>
To the extent possible under law, the editors have waived all copyright
and related or neighboring rights to this work.
In addition, as of 14 May 2015,
the editors have made this specification available under the
<a href="http:https://www.openwebfoundation.org/legal/the-owf-1-0-agreements/owfa-1-0" rel="license">Open Web Foundation Agreement Version 1.0</a>,
which is available at http:https://www.openwebfoundation.org/legal/the-owf-1-0-agreements/owfa-1-0.
Parts of this work may be from another specification document. If so, those parts are instead covered by the license of that specification document.
</p>
<hr title="Separator for header">
</div>
<h2 class="no-num no-toc no-ref heading settled" id="abstract"><span class="content">Abstract</span></h2>
<div class="p-summary" data-fill-with="abstract">
<p>This specification describes support for accessing virtual reality devices, including sensors and head-mounted displays on the Web.</p>
</div>
<div data-fill-with="at-risk"></div>
<h2 class="no-num no-toc no-ref heading settled" id="contents"><span class="content">Table of Contents</span></h2>
<div data-fill-with="table-of-contents" role="navigation">
<ul class="toc" role="directory">
<li><a href="#intro"><span class="secno">1</span> <span class="content">Introduction</span></a>
<li><a href="#devtypes"><span class="secno">2</span> <span class="content">Supported Device Types</span></a>
<li><a href="#security"><span class="secno">3</span> <span class="content">Security</span></a>
<li><a href="#dom"><span class="secno">4</span> <span class="content">DOM Interfaces</span></a>
<ul class="toc">
<li><a href="#vreye"><span class="secno">4.1</span> <span class="content">VREye</span></a>
<li><a href="#vrfieldofview"><span class="secno">4.2</span> <span class="content">VRFieldOfView</span></a>
<li><a href="#vrpositionstate"><span class="secno">4.3</span> <span class="content">VRPositionState</span></a>
<ul class="toc">
<li><a href="#vrpositionstateattributes"><span class="secno">4.3.1</span> <span class="content">Attributes</span></a>
</ul>
<li><a href="#vreyeparameters"><span class="secno">4.4</span> <span class="content">VREyeParameters</span></a>
<ul class="toc">
<li><a href="#vreyeparametersattributes"><span class="secno">4.4.1</span> <span class="content">Attributes</span></a>
</ul>
<li><a href="#vrdevice"><span class="secno">4.5</span> <span class="content">VRDevice</span></a>
<ul class="toc">
<li><a href="#vrdeviceattributes"><span class="secno">4.5.1</span> <span class="content">Attributes</span></a>
</ul>
<li><a href="#hmdvrdevice"><span class="secno">4.6</span> <span class="content">HMDVRDevice</span></a>
<ul class="toc">
<li><a href="#hmdvrdevicemethods"><span class="secno">4.6.1</span> <span class="content">Methods</span></a>
</ul>
<li><a href="#positionsensorvrdevice"><span class="secno">4.7</span> <span class="content">PositionSensorVRDevice</span></a>
<ul class="toc">
<li><a href="#positionsensorvrdevicemethods"><span class="secno">4.7.1</span> <span class="content">Methods</span></a>
</ul>
<li><a href="#navigator-interface-extension"><span class="secno">4.8</span> <span class="content">Navigator Interface extension</span></a>
<ul class="toc">
<li><a href="#navigatormethods"><span class="secno">4.8.1</span> <span class="content">Methods</span></a>
</ul>
</ul>
<li><a href="#ack"><span class="secno">5</span> <span class="content">Acknowledgements</span></a>
<li><a href="#conformance"><span class="secno"></span> <span class="content">
Conformance</span></a>
<li><a href="#index"><span class="secno"></span> <span class="content">Index</span></a>
<ul class="toc">
<li><a href="#index-defined-here"><span class="secno"></span> <span class="content">Terms defined by this specification</span></a>
<li><a href="#index-defined-elsewhere"><span class="secno"></span> <span class="content">Terms defined by reference</span></a>
</ul>
<li><a href="#references"><span class="secno"></span> <span class="content">References</span></a>
<ul class="toc">
<li><a href="#normative"><span class="secno"></span> <span class="content">Normative References</span></a>
</ul>
<li><a href="#idl-index"><span class="secno"></span> <span class="content">IDL Index</span></a>
</ul></div>
<main>
<h2 class="heading settled" data-level="1" id="intro"><span class="secno">1. </span><span class="content">Introduction</span><a class="self-link" href="#intro"></a></h2>
<p>Hardware that enables Virtual Reality applications requires high-precision, low-latency interfaces to deliver an acceptable experience.
Other interfaces, such as device orientation events, can be repurposed to surface VR input but doing so dilutes the interface’s original
intent and often does not provide the precision necessary for high-quality VR. The WebVR API provides purpose-built interfaces
to VR hardware to allow developers to build compelling, comfortable VR experiences.</p>
<h2 class="heading settled" data-level="2" id="devtypes"><span class="secno">2. </span><span class="content">Supported Device Types</span><a class="self-link" href="#devtypes"></a></h2>
<p>At this time there are two defined variants of VRDevice, each of which is intended to describe a specific capability of a piece of hardware
rather than all aspects of that hardware. For example, a typical Head-Mounted Display such as an Oculus Rift will be exposed as two VRDevices:
An HMDVRDevice that describes the optical properties of the device, including Field of View and Interpupillary Distance, and a
PositionSensorVRDevice, which describes the HMD’s position and orientation in space.</p>
<p>A PositionSensorVRDevice could also be provided without a corresponding HMDVRDevice to represent a piece of hardware that tracks position
but does not have a display, such as a Six-degrees-of-freedom controller.</p>
<p>Additional VRDevice types may be added over time to expose new hardware types or features as they becomes available to consumers.
Eye tracking is an example of a potential future interface.</p>
<h2 class="heading settled" data-level="3" id="security"><span class="secno">3. </span><span class="content">Security</span><a class="self-link" href="#security"></a></h2>
<p>Some information about security considerations here.</p>
<h2 class="heading settled" data-level="4" id="dom"><span class="secno">4. </span><span class="content">DOM Interfaces</span><a class="self-link" href="#dom"></a></h2>
<p>This section describes the interfaces and functionality added to the DOM to support runtime access to the functionality described above.</p>
<h3 class="heading settled" data-level="4.1" id="vreye"><span class="secno">4.1. </span><span class="content">VREye</span><a class="self-link" href="#vreye"></a></h3>
<pre class="idl">enum <dfn class="idl-code" data-dfn-type="enum" data-export="" data-global-name="" id="enumdef-vreye">VREye<a class="self-link" href="#enumdef-vreye"></a></dfn> { "left", "right" };
</pre>
<h3 class="heading settled" data-level="4.2" id="vrfieldofview"><span class="secno">4.2. </span><span class="content">VRFieldOfView</span><a class="self-link" href="#vrfieldofview"></a></h3>
<p>The <code class="idl"><a data-link-type="idl" href="#vrfieldofview0">VRFieldOfView</a></code> interface represents a field of view, as given by 4 degrees describing the view from a center point.</p>
<pre class="idl">interface <dfn class="idl-code" data-dfn-type="interface" data-export="" data-global-name="" id="vrfieldofviewreadonly">VRFieldOfViewReadOnly<a class="self-link" href="#vrfieldofviewreadonly"></a></dfn> {
readonly attribute double <dfn class="idl-code" data-dfn-for="VRFieldOfViewReadOnly" data-dfn-type="attribute" data-export="" data-global-name="VRFieldOfViewReadOnly<interface>/upDegrees<attribute>" data-readonly="" data-type="double " id="dom-vrfieldofviewreadonly-updegrees">upDegrees<a class="self-link" href="#dom-vrfieldofviewreadonly-updegrees"></a></dfn>;
readonly attribute double <dfn class="idl-code" data-dfn-for="VRFieldOfViewReadOnly" data-dfn-type="attribute" data-export="" data-global-name="VRFieldOfViewReadOnly<interface>/rightDegrees<attribute>" data-readonly="" data-type="double " id="dom-vrfieldofviewreadonly-rightdegrees">rightDegrees<a class="self-link" href="#dom-vrfieldofviewreadonly-rightdegrees"></a></dfn>;
readonly attribute double <dfn class="idl-code" data-dfn-for="VRFieldOfViewReadOnly" data-dfn-type="attribute" data-export="" data-global-name="VRFieldOfViewReadOnly<interface>/downDegrees<attribute>" data-readonly="" data-type="double " id="dom-vrfieldofviewreadonly-downdegrees">downDegrees<a class="self-link" href="#dom-vrfieldofviewreadonly-downdegrees"></a></dfn>;
readonly attribute double <dfn class="idl-code" data-dfn-for="VRFieldOfViewReadOnly" data-dfn-type="attribute" data-export="" data-global-name="VRFieldOfViewReadOnly<interface>/leftDegrees<attribute>" data-readonly="" data-type="double " id="dom-vrfieldofviewreadonly-leftdegrees">leftDegrees<a class="self-link" href="#dom-vrfieldofviewreadonly-leftdegrees"></a></dfn>;
};
dictionary <dfn class="idl-code" data-dfn-type="dictionary" data-export="" data-global-name="" id="dictdef-vrfieldofviewinit">VRFieldOfViewInit<a class="self-link" href="#dictdef-vrfieldofviewinit"></a></dfn> {
double <dfn class="idl-code" data-default="0.0" data-dfn-for="VRFieldOfViewInit" data-dfn-type="dict-member" data-export="" data-global-name="VRFieldOfViewInit<dictionary>/upDegrees<dict-member>" data-type="double " id="dom-vrfieldofviewinit-updegrees">upDegrees<a class="self-link" href="#dom-vrfieldofviewinit-updegrees"></a></dfn> = 0.0;
double <dfn class="idl-code" data-default="0.0" data-dfn-for="VRFieldOfViewInit" data-dfn-type="dict-member" data-export="" data-global-name="VRFieldOfViewInit<dictionary>/rightDegrees<dict-member>" data-type="double " id="dom-vrfieldofviewinit-rightdegrees">rightDegrees<a class="self-link" href="#dom-vrfieldofviewinit-rightdegrees"></a></dfn> = 0.0;
double <dfn class="idl-code" data-default="0.0" data-dfn-for="VRFieldOfViewInit" data-dfn-type="dict-member" data-export="" data-global-name="VRFieldOfViewInit<dictionary>/downDegrees<dict-member>" data-type="double " id="dom-vrfieldofviewinit-downdegrees">downDegrees<a class="self-link" href="#dom-vrfieldofviewinit-downdegrees"></a></dfn> = 0.0;
double <dfn class="idl-code" data-default="0.0" data-dfn-for="VRFieldOfViewInit" data-dfn-type="dict-member" data-export="" data-global-name="VRFieldOfViewInit<dictionary>/leftDegrees<dict-member>" data-type="double " id="dom-vrfieldofviewinit-leftdegrees">leftDegrees<a class="self-link" href="#dom-vrfieldofviewinit-leftdegrees"></a></dfn> = 0.0;
};
[<dfn class="idl-code" data-dfn-for="VRFieldOfView" data-dfn-type="constructor" data-export="" data-global-name="VRFieldOfView<interface>/VRFieldOfView(fov)<constructor>" data-lt="VRFieldOfView(fov)" id="dom-vrfieldofview-vrfieldofviewfov">Constructor<a class="self-link" href="#dom-vrfieldofview-vrfieldofviewfov"></a></dfn>(optional <a data-link-type="idl-name" href="#dictdef-vrfieldofviewinit">VRFieldOfViewInit</a> <dfn class="idl-code" data-dfn-for="VRFieldOfView/VRFieldOfView(fov)" data-dfn-type="argument" data-export="" data-global-name="VRFieldOfView<interface>/VRFieldOfView(fov)<method>/fov<argument>" id="dom-vrfieldofview-vrfieldofviewfov-fov">fov<a class="self-link" href="#dom-vrfieldofview-vrfieldofviewfov-fov"></a></dfn>),
<dfn class="idl-code" data-dfn-for="VRFieldOfView" data-dfn-type="constructor" data-export="" data-global-name="VRFieldOfView<interface>/VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)<constructor>" data-lt="VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)" id="dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees">Constructor<a class="self-link" href="#dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees"></a></dfn>(double <dfn class="idl-code" data-dfn-for="VRFieldOfView/VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)" data-dfn-type="argument" data-export="" data-global-name="VRFieldOfView<interface>/VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)<method>/upDegrees<argument>" id="dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees-updegrees">upDegrees<a class="self-link" href="#dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees-updegrees"></a></dfn>, double <dfn class="idl-code" data-dfn-for="VRFieldOfView/VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)" data-dfn-type="argument" data-export="" data-global-name="VRFieldOfView<interface>/VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)<method>/rightDegrees<argument>" id="dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees-rightdegrees">rightDegrees<a class="self-link" href="#dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees-rightdegrees"></a></dfn>, double <dfn class="idl-code" data-dfn-for="VRFieldOfView/VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)" data-dfn-type="argument" data-export="" data-global-name="VRFieldOfView<interface>/VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)<method>/downDegrees<argument>" id="dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees-downdegrees">downDegrees<a class="self-link" href="#dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees-downdegrees"></a></dfn>, double <dfn class="idl-code" data-dfn-for="VRFieldOfView/VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)" data-dfn-type="argument" data-export="" data-global-name="VRFieldOfView<interface>/VRFieldOfView(upDegrees, rightDegrees, downDegrees, leftDegrees)<method>/leftDegrees<argument>" id="dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees-leftdegrees">leftDegrees<a class="self-link" href="#dom-vrfieldofview-vrfieldofviewupdegrees-rightdegrees-downdegrees-leftdegrees-leftdegrees"></a></dfn>)]
interface <dfn class="idl-code" data-dfn-type="interface" data-export="" data-global-name="" id="vrfieldofview0">VRFieldOfView<a class="self-link" href="#vrfieldofview0"></a></dfn> : <a data-link-type="idl-name" href="#vrfieldofviewreadonly">VRFieldOfViewReadOnly</a> {
inherit attribute double <dfn class="idl-code" data-dfn-for="VRFieldOfView" data-dfn-type="attribute" data-export="" data-global-name="VRFieldOfView<interface>/upDegrees<attribute>" data-type="double " id="dom-vrfieldofview-updegrees">upDegrees<a class="self-link" href="#dom-vrfieldofview-updegrees"></a></dfn>;
inherit attribute double <dfn class="idl-code" data-dfn-for="VRFieldOfView" data-dfn-type="attribute" data-export="" data-global-name="VRFieldOfView<interface>/rightDegrees<attribute>" data-type="double " id="dom-vrfieldofview-rightdegrees">rightDegrees<a class="self-link" href="#dom-vrfieldofview-rightdegrees"></a></dfn>;
inherit attribute double <dfn class="idl-code" data-dfn-for="VRFieldOfView" data-dfn-type="attribute" data-export="" data-global-name="VRFieldOfView<interface>/downDegrees<attribute>" data-type="double " id="dom-vrfieldofview-downdegrees">downDegrees<a class="self-link" href="#dom-vrfieldofview-downdegrees"></a></dfn>;
inherit attribute double <dfn class="idl-code" data-dfn-for="VRFieldOfView" data-dfn-type="attribute" data-export="" data-global-name="VRFieldOfView<interface>/leftDegrees<attribute>" data-type="double " id="dom-vrfieldofview-leftdegrees">leftDegrees<a class="self-link" href="#dom-vrfieldofview-leftdegrees"></a></dfn>;
};
</pre>
<div class="example" id="example-32e55d23"><a class="self-link" href="#example-32e55d23"></a>
The following code snippet creates a WebGL-compatible projection matrix from a
<code class="idl"><a data-link-type="idl" href="#vrfieldofview0">VRFieldOfView</a></code>.
<pre>function fieldOfViewToProjectionMatrix(fov, zNear, zFar) {
var upTan = Math.tan(fov.upDegrees * Math.PI / 180.0);
var downTan = Math.tan(fov.downDegrees * Math.PI / 180.0);
var leftTan = Math.tan(fov.leftDegrees * Math.PI / 180.0);
var rightTan = Math.tan(fov.rightDegrees * Math.PI / 180.0);
var xScale = 2.0 / (leftTan + rightTan);
var yScale = 2.0 / (upTan + downTan);
var out = new Float32Array(16);
out[0] = xScale;
out[1] = 0.0;
out[2] = 0.0;
out[3] = 0.0;
out[4] = 0.0;
out[5] = yScale;
out[6] = 0.0;
out[7] = 0.0;
out[8] = -((leftTan - rightTan) * xScale * 0.5);
out[9] = ((upTan - downTan) * yScale * 0.5);
out[10] = -(zNear + zFar) / (zFar - zNear);
out[11] = -1.0;
out[12] = 0.0;
out[13] = 0.0;
out[14] = -(2.0 * zFar * zNear) / (zFar - zNear);
out[15] = 0.0;
return out;
}
</pre>
</div>
<h3 class="heading settled" data-level="4.3" id="vrpositionstate"><span class="secno">4.3. </span><span class="content">VRPositionState</span><a class="self-link" href="#vrpositionstate"></a></h3>
<p>The <code class="idl"><a data-link-type="idl" href="#vrpositionstate0">VRPositionState</a></code> interface represents a sensor’s state at a given timestamp.</p>
<pre class="idl">interface <dfn class="idl-code" data-dfn-type="interface" data-export="" data-global-name="" id="vrpositionstate0">VRPositionState<a class="self-link" href="#vrpositionstate0"></a></dfn> {
readonly attribute double <a class="idl-code" data-global-name="VRPositionState<interface>/timeStamp<attribute>" data-link-type="attribute" data-readonly="" data-type="double " href="#dom-vrpositionstate-timestamp">timeStamp</a>;
readonly attribute boolean <a class="idl-code" data-global-name="VRPositionState<interface>/hasPosition<attribute>" data-link-type="attribute" data-readonly="" data-type="boolean " href="#dom-vrpositionstate-hasposition">hasPosition</a>;
readonly attribute <a data-link-type="idl-name" href="http:https://dev.w3.org/fxtf/geometry/#dompoint">DOMPoint</a>? <a class="idl-code" data-global-name="VRPositionState<interface>/position<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMPoint? " href="#dom-vrpositionstate-position">position</a>;
readonly attribute <a data-link-type="idl-name" href="http:https://dev.w3.org/fxtf/geometry/#dompoint">DOMPoint</a>? <a class="idl-code" data-global-name="VRPositionState<interface>/linearVelocity<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMPoint? " href="#dom-vrpositionstate-linearvelocity">linearVelocity</a>;
readonly attribute <a data-link-type="idl-name" href="http:https://dev.w3.org/fxtf/geometry/#dompoint">DOMPoint</a>? <a class="idl-code" data-global-name="VRPositionState<interface>/linearAcceleration<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMPoint? " href="#dom-vrpositionstate-linearacceleration">linearAcceleration</a>;
readonly attribute boolean <a class="idl-code" data-global-name="VRPositionState<interface>/hasOrientation<attribute>" data-link-type="attribute" data-readonly="" data-type="boolean " href="#dom-vrpositionstate-hasorientation">hasOrientation</a>;
// XXX should be DOMQuaternion as soon as we add that
readonly attribute <a data-link-type="idl-name" href="http:https://dev.w3.org/fxtf/geometry/#dompoint">DOMPoint</a>? <a class="idl-code" data-global-name="VRPositionState<interface>/orientation<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMPoint? " href="#dom-vrpositionstate-orientation">orientation</a>;
readonly attribute <a data-link-type="idl-name" href="http:https://dev.w3.org/fxtf/geometry/#dompoint">DOMPoint</a>? <a class="idl-code" data-global-name="VRPositionState<interface>/angularVelocity<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMPoint? " href="#dom-vrpositionstate-angularvelocity">angularVelocity</a>;
readonly attribute <a data-link-type="idl-name" href="http:https://dev.w3.org/fxtf/geometry/#dompoint">DOMPoint</a>? <a class="idl-code" data-global-name="VRPositionState<interface>/angularAcceleration<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMPoint? " href="#dom-vrpositionstate-angularacceleration">angularAcceleration</a>;
};
</pre>
<h4 class="heading settled" data-level="4.3.1" id="vrpositionstateattributes"><span class="secno">4.3.1. </span><span class="content">Attributes</span><a class="self-link" href="#vrpositionstateattributes"></a></h4>
<p><dfn class="idl-code" data-dfn-for="VRPositionState" data-dfn-type="attribute" data-export="" id="dom-vrpositionstate-timestamp">timeStamp<a class="self-link" href="#dom-vrpositionstate-timestamp"></a></dfn>
Monotonically increasing value that allows the author to determine if position
state data been updated from the hardware. Since values are monotonically
increasing they can be compared to determine the ordering of updates, as newer
values will always be greater than or equal to older values.</p>
<p><dfn class="idl-code" data-dfn-for="VRPositionState" data-dfn-type="attribute" data-export="" id="dom-vrpositionstate-hasposition">hasPosition<a class="self-link" href="#dom-vrpositionstate-hasposition"></a></dfn>
True if the <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-position">position</a></code> attribute is valid. If false, <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-position">position</a></code> MUST be null.</p>
<p><dfn class="idl-code" data-dfn-for="VRPositionState" data-dfn-type="attribute" data-export="" id="dom-vrpositionstate-position">position<a class="self-link" href="#dom-vrpositionstate-position"></a></dfn>
Position of the sensor at <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-timestamp">timeStamp</a></code> as a 3D vector. Position is given in
meters from an origin point, which is either the position the sensor was first
read at or the position of the sensor at the point that resetSensor was last
called. The coordinate system uses these axis definitions:</p>
<ul>
<li>Positive X is to the user’s right.
<li>Positive Y is up.
<li>Positive Z is behind the user.
</ul>
All positions are given relative to the identity orientation. The w component
MUST be 0. May be null if the sensor is incapable of providing positional data.
<p><dfn class="idl-code" data-dfn-for="VRPositionState" data-dfn-type="attribute" data-export="" id="dom-vrpositionstate-linearvelocity">linearVelocity<a class="self-link" href="#dom-vrpositionstate-linearvelocity"></a></dfn>
Linear velocity of the sensor at <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-timestamp">timeStamp</a></code>. The w component MUST be 0.
May be null if the sensor is incapable of providing linear velocity.</p>
<p><dfn class="idl-code" data-dfn-for="VRPositionState" data-dfn-type="attribute" data-export="" id="dom-vrpositionstate-linearacceleration">linearAcceleration<a class="self-link" href="#dom-vrpositionstate-linearacceleration"></a></dfn>
Linear acceleration of the sensor at <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-timestamp">timeStamp</a></code>. The w component MUST be 0.
May be null if the sensor is incapable of providing linear acceleration.</p>
<p><dfn class="idl-code" data-dfn-for="VRPositionState" data-dfn-type="attribute" data-export="" id="dom-vrpositionstate-hasorientation">hasOrientation<a class="self-link" href="#dom-vrpositionstate-hasorientation"></a></dfn>
True if the <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-orientation">orientation</a></code> attribute is valid. If false, <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-orientation">orientation</a></code> MUST be
null.</p>
<p><dfn class="idl-code" data-dfn-for="VRPositionState" data-dfn-type="attribute" data-export="" id="dom-vrpositionstate-orientation">orientation<a class="self-link" href="#dom-vrpositionstate-orientation"></a></dfn>
Orientation of the sensor at <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-timestamp">timeStamp</a></code> as a quaternion. The orientation yaw
(rotation around the Y axis) is relative to the initial yaw of the sensor when
it was first read or the yaw of the sensor at the point that resetSensor was
last called. An orientation of {x: 0, y: 0, z: 0, w: 1} is considered to be
"forward". May be null if the sensor is incapable of providing
orientation data.</p>
<p><dfn class="idl-code" data-dfn-for="VRPositionState" data-dfn-type="attribute" data-export="" id="dom-vrpositionstate-angularvelocity">angularVelocity<a class="self-link" href="#dom-vrpositionstate-angularvelocity"></a></dfn>
Angular velocity of the sensor at <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-timestamp">timeStamp</a></code>. The w component MUST be 0.
May be null if the sensor is incapable of providing angular velocity.</p>
<p><dfn class="idl-code" data-dfn-for="VRPositionState" data-dfn-type="attribute" data-export="" id="dom-vrpositionstate-angularacceleration">angularAcceleration<a class="self-link" href="#dom-vrpositionstate-angularacceleration"></a></dfn>
Angular acceleration of the sensor at <code class="idl"><a data-link-type="idl" href="#dom-vrpositionstate-timestamp">timeStamp</a></code>. The w component MUST be 0.
May be null if the sensor is incapable of providing angular acceleration.</p>
<h3 class="heading settled" data-level="4.4" id="vreyeparameters"><span class="secno">4.4. </span><span class="content">VREyeParameters</span><a class="self-link" href="#vreyeparameters"></a></h3>
<p>The <code class="idl"><a data-link-type="idl" href="#vreyeparameters0">VREyeParameters</a></code> interface represents all the information required to correctly render a scene for a given eye.</p>
<pre class="idl">interface <dfn class="idl-code" data-dfn-type="interface" data-export="" data-global-name="" id="vreyeparameters0">VREyeParameters<a class="self-link" href="#vreyeparameters0"></a></dfn> {
/* These values are expected to be static per-device/per-user. */
readonly attribute <a data-link-type="idl-name" href="#vrfieldofview0">VRFieldOfView</a> <a class="idl-code" data-global-name="VREyeParameters<interface>/minimumFieldOfView<attribute>" data-link-type="attribute" data-readonly="" data-type="VRFieldOfView " href="#dom-vreyeparameters-minimumfieldofview">minimumFieldOfView</a>;
readonly attribute <a data-link-type="idl-name" href="#vrfieldofview0">VRFieldOfView</a> <a class="idl-code" data-global-name="VREyeParameters<interface>/maximumFieldOfView<attribute>" data-link-type="attribute" data-readonly="" data-type="VRFieldOfView " href="#dom-vreyeparameters-maximumfieldofview">maximumFieldOfView</a>;
readonly attribute <a data-link-type="idl-name" href="#vrfieldofview0">VRFieldOfView</a> <a class="idl-code" data-global-name="VREyeParameters<interface>/recommendedFieldOfView<attribute>" data-link-type="attribute" data-readonly="" data-type="VRFieldOfView " href="#dom-vreyeparameters-recommendedfieldofview">recommendedFieldOfView</a>;
readonly attribute <a data-link-type="idl-name" href="http:https://dev.w3.org/fxtf/geometry/#dompoint">DOMPoint</a> <a class="idl-code" data-global-name="VREyeParameters<interface>/eyeTranslation<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMPoint " href="#dom-vreyeparameters-eyetranslation">eyeTranslation</a>;
/* These values will vary after a FOV has been set. */
readonly attribute <a data-link-type="idl-name" href="#vrfieldofview0">VRFieldOfView</a> <a class="idl-code" data-global-name="VREyeParameters<interface>/currentFieldOfView<attribute>" data-link-type="attribute" data-readonly="" data-type="VRFieldOfView " href="#dom-vreyeparameters-currentfieldofview">currentFieldOfView</a>;
readonly attribute <a data-link-type="idl-name" href="http:https://dev.w3.org/fxtf/geometry/#domrect">DOMRect</a> <a class="idl-code" data-global-name="VREyeParameters<interface>/renderRect<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMRect " href="#dom-vreyeparameters-renderrect">renderRect</a>;
};
</pre>
<h4 class="heading settled" data-level="4.4.1" id="vreyeparametersattributes"><span class="secno">4.4.1. </span><span class="content">Attributes</span><a class="self-link" href="#vreyeparametersattributes"></a></h4>
<p><dfn class="idl-code" data-dfn-for="VREyeParameters" data-dfn-type="attribute" data-export="" id="dom-vreyeparameters-minimumfieldofview">minimumFieldOfView<a class="self-link" href="#dom-vreyeparameters-minimumfieldofview"></a></dfn>
Describes the minimum supported field of view for the eye.</p>
<p><dfn class="idl-code" data-dfn-for="VREyeParameters" data-dfn-type="attribute" data-export="" id="dom-vreyeparameters-maximumfieldofview">maximumFieldOfView<a class="self-link" href="#dom-vreyeparameters-maximumfieldofview"></a></dfn>
Describes the maximum supported field of view for the eye.</p>
<p><dfn class="idl-code" data-dfn-for="VREyeParameters" data-dfn-type="attribute" data-export="" id="dom-vreyeparameters-recommendedfieldofview">recommendedFieldOfView<a class="self-link" href="#dom-vreyeparameters-recommendedfieldofview"></a></dfn>
Describes the recommended field of view for the eye. It is RECOMMENDED that this
be set to a value based on user calibration.</p>
<p><dfn class="idl-code" data-dfn-for="VREyeParameters" data-dfn-type="attribute" data-export="" id="dom-vreyeparameters-eyetranslation">eyeTranslation<a class="self-link" href="#dom-vreyeparameters-eyetranslation"></a></dfn>
Offset from the center of the user’s head to the eye in meters. This value SHOULD
represent the user’s interpupillary distance (IPD), but may also represent the
distance from the center point of the headset to the center point of the lens for
the given eye. Values for the left eye MUST be negative; values for the right
eye MUST be positive.</p>
<p><dfn class="idl-code" data-dfn-for="VREyeParameters" data-dfn-type="attribute" data-export="" id="dom-vreyeparameters-currentfieldofview">currentFieldOfView<a class="self-link" href="#dom-vreyeparameters-currentfieldofview"></a></dfn>
The current field of view for the eye, as specified by setFieldOfView.
Defaults to <code class="idl"><a data-link-type="idl" href="#dom-vreyeparameters-recommendedfieldofview">recommendedFieldOfView</a></code>.</p>
<p><dfn class="idl-code" data-dfn-for="VREyeParameters" data-dfn-type="attribute" data-export="" id="dom-vreyeparameters-renderrect">renderRect<a class="self-link" href="#dom-vreyeparameters-renderrect"></a></dfn>
Describes the viewport of a canvas into which visuals for this eye should be
rendered. The <code class="idl"><a data-link-type="idl" href="#dom-vreyeparameters-renderrect">renderRect</a></code> for the left eye and right eye MUST NOT overlap,
and the <code class="idl"><a data-link-type="idl" href="#dom-vreyeparameters-renderrect">renderRect</a></code> for the rightEye MUST be to the right of the
<code class="idl"><a data-link-type="idl" href="#dom-vreyeparameters-renderrect">renderRect</a></code> for the left eye.</p>
<p>The union of the <code class="idl"><a data-link-type="idl" href="#dom-vreyeparameters-renderrect">renderRect</a></code>s for both eyes SHOULD describe the optimal
rendering resolution for the HMD when using <code class="idl"><a data-link-type="idl" href="#dom-vreyeparameters-currentfieldofview">currentFieldOfView</a></code>, such that
the center of the user’s view maintains a 1:1 pixel ratio after any distortion
to correct for HMD optics applied to the rendering.</p>
<div class="example" id="example-68926c2f"><a class="self-link" href="#example-68926c2f"></a>
Many HMDs will distort the rendered image to counteract undesired effects
introduced by the headset optics. Because of this the optimal resolution of the
canvas will often be larger than the HMD’s physical resolution to ensure that
the final image presented to the user has a 1:1 pixel ratio at the center of the
user’s view. The optimal canvas resolution can be calculated from the
<code class="idl"><a data-link-type="idl" href="#dom-vreyeparameters-renderrect">renderRect</a></code> for both eyes as follows:
<pre>var leftEyeParams = hmd.getEyeParameters("left");
var rightEyeParams = hmd.getEyeParameters("right");
var leftEyeRect = leftEyeParams.renderRect;
var rightEyeRect = rightEyeParams.renderRect;
canvas.width = rightEyeRect.x + rightEyeRect.width;
canvas.height = Math.max(leftEyeRect.y + leftEyeRect.height,
rightEyeRect.y + rightEyeRect.height);
</pre>
</div>
<h3 class="heading settled" data-level="4.5" id="vrdevice"><span class="secno">4.5. </span><span class="content">VRDevice</span><a class="self-link" href="#vrdevice"></a></h3>
<p>The <code class="idl"><a data-link-type="idl" href="#vrdevice0">VRDevice</a></code> interface forms the base of all VR devices supported by this API. It includes generic information such as device IDs and descriptions.</p>
<pre class="idl">interface <dfn class="idl-code" data-dfn-type="interface" data-export="" data-global-name="" id="vrdevice0">VRDevice<a class="self-link" href="#vrdevice0"></a></dfn> {
readonly attribute DOMString <a class="idl-code" data-global-name="VRDevice<interface>/hardwareUnitId<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMString " href="#dom-vrdevice-hardwareunitid">hardwareUnitId</a>;
readonly attribute DOMString <a class="idl-code" data-global-name="VRDevice<interface>/deviceId<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMString " href="#dom-vrdevice-deviceid">deviceId</a>;
readonly attribute DOMString <a class="idl-code" data-global-name="VRDevice<interface>/deviceName<attribute>" data-link-type="attribute" data-readonly="" data-type="DOMString " href="#dom-vrdevice-devicename">deviceName</a>;
};
</pre>
<h4 class="heading settled" data-level="4.5.1" id="vrdeviceattributes"><span class="secno">4.5.1. </span><span class="content">Attributes</span><a class="self-link" href="#vrdeviceattributes"></a></h4>
<p><dfn class="idl-code" data-dfn-for="VRDevice" data-dfn-type="attribute" data-export="" id="dom-vrdevice-hardwareunitid">hardwareUnitId<a class="self-link" href="#dom-vrdevice-hardwareunitid"></a></dfn>
An identifier for the distinct hardware unit that this <code class="idl"><a data-link-type="idl" href="#vrdevice0">VRDevice</a></code> is a part
of. Any <code class="idl"><a data-link-type="idl" href="#vrdevice0">VRDevice</a></code> that comes from the same physical piece of hardware will
have the same <code class="idl"><a data-link-type="idl" href="#dom-vrdevice-hardwareunitid">hardwareUnitId</a></code>.</p>
<p><dfn class="idl-code" data-dfn-for="VRDevice" data-dfn-type="attribute" data-export="" id="dom-vrdevice-deviceid">deviceId<a class="self-link" href="#dom-vrdevice-deviceid"></a></dfn>
An identifier for this distinct sensor/device on a physical hardware device.
This shouldn’t change across browser restarts, allowing configuration data to be
saved based on it.</p>
<p><dfn class="idl-code" data-dfn-for="VRDevice" data-dfn-type="attribute" data-export="" id="dom-vrdevice-devicename">deviceName<a class="self-link" href="#dom-vrdevice-devicename"></a></dfn>
A user-readable name identifying the device.</p>
<h3 class="heading settled" data-level="4.6" id="hmdvrdevice"><span class="secno">4.6. </span><span class="content">HMDVRDevice</span><a class="self-link" href="#hmdvrdevice"></a></h3>
<p>The <code class="idl"><a data-link-type="idl" href="#hmdvrdevice0">HMDVRDevice</a></code> interface represents a <code class="idl"><a data-link-type="idl" href="#vrdevice0">VRDevice</a></code> for a head-mounted display. It contains configuration and information about the HMD.</p>
<pre class="idl">interface <dfn class="idl-code" data-dfn-type="interface" data-export="" data-global-name="" id="hmdvrdevice0">HMDVRDevice<a class="self-link" href="#hmdvrdevice0"></a></dfn> : <a data-link-type="idl-name" href="#vrdevice0">VRDevice</a> {
<a data-link-type="idl-name" href="#vreyeparameters0">VREyeParameters</a> <a class="idl-code" data-global-name="HMDVRDevice<interface>/getEyeParameters(whichEye)<method>" data-link-type="method" href="#dom-hmdvrdevice-geteyeparameterswhicheye">getEyeParameters</a>(<a data-link-type="idl-name" href="#enumdef-vreye">VREye</a> <dfn class="idl-code" data-dfn-for="HMDVRDevice/getEyeParameters(whichEye)" data-dfn-type="argument" data-export="" data-global-name="HMDVRDevice<interface>/getEyeParameters(whichEye)<method>/whichEye<argument>" id="dom-hmdvrdevice-geteyeparameterswhicheye-whicheye">whichEye<a class="self-link" href="#dom-hmdvrdevice-geteyeparameterswhicheye-whicheye"></a></dfn>);
void <a class="idl-code" data-global-name="HMDVRDevice<interface>/setFieldOfView(leftFOV, rightFOV, zNear, zFar)<method>/setFieldOfView(leftFOV, rightFOV, zNear)<method>/setFieldOfView(leftFOV, rightFOV)<method>/setFieldOfView(leftFOV)<method>/setFieldOfView()<method>" data-link-type="method" href="#dom-hmdvrdevice-setfieldofviewleftfov-rightfov-znear-zfar">setFieldOfView</a>(optional <a data-link-type="idl-name" href="#dictdef-vrfieldofviewinit">VRFieldOfViewInit</a> <dfn class="idl-code" data-dfn-for="HMDVRDevice/setFieldOfView(leftFOV, rightFOV, zNear, zFar)" data-dfn-type="argument" data-export="" data-global-name="HMDVRDevice<interface>/setFieldOfView(leftFOV, rightFOV, zNear, zFar)<method>/leftFOV<argument>" id="dom-hmdvrdevice-setfieldofviewleftfov-rightfov-znear-zfar-leftfov">leftFOV<a class="self-link" href="#dom-hmdvrdevice-setfieldofviewleftfov-rightfov-znear-zfar-leftfov"></a></dfn>,
optional <a data-link-type="idl-name" href="#dictdef-vrfieldofviewinit">VRFieldOfViewInit</a> <dfn class="idl-code" data-dfn-for="HMDVRDevice/setFieldOfView(leftFOV, rightFOV, zNear, zFar)" data-dfn-type="argument" data-export="" data-global-name="HMDVRDevice<interface>/setFieldOfView(leftFOV, rightFOV, zNear, zFar)<method>/rightFOV<argument>" id="dom-hmdvrdevice-setfieldofviewleftfov-rightfov-znear-zfar-rightfov">rightFOV<a class="self-link" href="#dom-hmdvrdevice-setfieldofviewleftfov-rightfov-znear-zfar-rightfov"></a></dfn>,
optional double <dfn class="idl-code" data-dfn-for="HMDVRDevice/setFieldOfView(leftFOV, rightFOV, zNear, zFar)" data-dfn-type="argument" data-export="" data-global-name="HMDVRDevice<interface>/setFieldOfView(leftFOV, rightFOV, zNear, zFar)<method>/zNear<argument>" id="dom-hmdvrdevice-setfieldofviewleftfov-rightfov-znear-zfar-znear">zNear<a class="self-link" href="#dom-hmdvrdevice-setfieldofviewleftfov-rightfov-znear-zfar-znear"></a></dfn> = 0.01,
optional double <dfn class="idl-code" data-dfn-for="HMDVRDevice/setFieldOfView(leftFOV, rightFOV, zNear, zFar)" data-dfn-type="argument" data-export="" data-global-name="HMDVRDevice<interface>/setFieldOfView(leftFOV, rightFOV, zNear, zFar)<method>/zFar<argument>" id="dom-hmdvrdevice-setfieldofviewleftfov-rightfov-znear-zfar-zfar">zFar<a class="self-link" href="#dom-hmdvrdevice-setfieldofviewleftfov-rightfov-znear-zfar-zfar"></a></dfn> = 10000.0);
};
</pre>
<h4 class="heading settled" data-level="4.6.1" id="hmdvrdevicemethods"><span class="secno">4.6.1. </span><span class="content">Methods</span><a class="self-link" href="#hmdvrdevicemethods"></a></h4>
<p><dfn class="idl-code" data-dfn-for="HMDVRDevice" data-dfn-type="method" data-export="" data-lt="getEyeParameters(whichEye)" id="dom-hmdvrdevice-geteyeparameterswhicheye">getEyeParameters(VREye whichEye)<a class="self-link" href="#dom-hmdvrdevice-geteyeparameterswhicheye"></a></dfn>