<model-viewer>
relies on standardized features of the Web Platform to do a lot
of what it does. Some of these features are very new and don't exist in all
browsers yet. In order to maximize browser compatibility, you should install
polyfills to fill in the
gaps for some of the newest features.
The following emerging standard web platform APIs are required by
<model-viewer>
:
- Custom Elements (CanIUse, Platform Status)
- Shadow DOM (CanIUse, Platform Status)
- Intersection Observer (CanIUse, Platform Status)
- Fullscreen API (CanIUse, Platform Status)
The following emerging web platform API is optional, and will be used by
<model-viewer>
if it is detected on the page:
Additionally, the following highly experimental and volatile APIs are needed to enable in-browser AR (currently available in Chrome Canary only):
Some browser support for these features can be enabled with polyfills. Any polyfills that faithfully implement the required platform features should be fine. The following is a selection of recommended polyfill implementations:
- Web Components Polyfill (includes Custom Elements and Shadow DOM)
- Resize Observer Polyfill
- Intersection Observer Polyfill
- Fullscreen Polyfill
Please keep in mind that your mileage may vary depending on the browsers you need to support and the fidelity of the polyfills used.
The Fullscreen API is only necessary for the experimental Web XR Device API-based AR mode. Since this is only available behind a flag in Chrome Dev today, it is not necessary to load a Fullscreen API polyfill in production scenarios.
If Resize Observer is available in the page, the <model-element>
will be able
to automatically recompute the scale and framing of its 3D content in many types
of scenarios where layout is changing (for example, when its parent container
changes size due to an animation or transition).
However, it is important to note that Resize Observer is optional because the polyfill is known to have performance consequences that might be considered unacceptable for some use cases (it uses a Mutation Observer that observes the whole document tree).
If Resize Observer is not available, the <model-element>
will fall back to
observing window resize
events. In this condition, you can force the element
to recompute its internal layout by dispatching a synthetic window resize
event.
If you are using the polyfills recommended above, you can install them with this NPM command:
npm i --save @webcomponents/webcomponentjs \
resize-observer-polyfill \
fullscreen-polyfill \
intersection-observer
Once you have them installed, it is generally required that you load them before the rest of your application code:
<!doctype>
<html>
<head>
<title>Polyfill Example</title>
<!-- The following libraries and polyfills are recommended to maximize browser support -->
<!-- NOTE: you must adjust the paths as appropriate for your project -->
<!-- Web Components polyfill is required to support Edge and Firefox < 63: -->
<script src="./node_modules/@webcomponents/webcomponentsjs/webcomponents-loader.js"></script>
<!-- Resize Observer polyfill is optional, and improves resize behavior in non-Chrome browsers: -->
<script src="./node_modules/resize-observer-polyfill/dist/ResizeObserver.js"></script>
<!-- Intersection Observer polyfill is required for Safari and IE11 -->
<script src="./node_modules/intersection-observer/intersection-observer.js"></script>
<!-- Fullscreen polyfill is required for using experimental AR features in Canary: -->
<script src="./node_modules/fullscreen-polyfill/dist/fullscreen.polyfill.js"></script>
</head>
<body>
<!-- etc -->
</body>
</html>
If you are using the "legacy" browser bundle, or otherwise targeting old
browsers such as Internet Explorer 11 with your build, you MUST also include
the Custom Elements ES5 Adapter in your document before loading <model-viewer>
.
The Adapter is included as part of the Web Components Polyfill, and can be included with a script tag:
<!-- Include the Custom Elements ES5 adapter shim if you are loading an IE11-compatible bundle -->
<script src="./node_modules/@webcomponents/webcomponentsjs/custom-elements-es5-adapter.js"></script>