VR & AR (WebXR)

Supported Devices

Needle Engine supports the full WebXR specification, including AR and VR. WebXR is an official web standard that brings immersive experiences to the web, with all the benefits of the web: no installation, no app store, no SDKs required.

All devices with a browser can run apps made with Needle. If the browser supports WebXR, your apps will automatically work in XR as well, using our built-in components. This includes desktop browsers, mobile browsers, many browsers on AR/VR headsets, but also other emerging technologies like Looking Glass displays, smart glasses, and more.

:::tip App-free iOS AR support via USDZ/QuickLook While iOS devices don't yet have official WebXR support, Needle supports creating AR experiences on iOS using Everywhere Actions. See the iOS section for more details. You can create rich, interactive experiences that work seamlessly in AR on iOS devices, even with the limitations that Apple has in place.

When you enter AR mode on iOS, Needle will automatically convert your scene to an USDZ file, which is then displayed in AR using Apple's QuickLook. Objects, materials, audio, animation and Everywhere Actions will be preserved. :::

The following table lists some of the devices that we verified to work with Needle Engine. When a new device comes out that supports WebXR, it will work with your apps out of the box. This is one of the big advantages of building with the browser as a platform – compatibility is not limited to a specific set of devices or SDKs.

Headset Device	Browser	Notes
Apple Vision Pro	✔️ Safari	hand tracking, support for transient pointer
Meta Quest 3	✔️ Meta Browser	hand tracking, support for sessiongranted1, passthrough, depth sensing, mesh tracking
Meta Quest 3S	✔️ Meta Browser	hand tracking, support for sessiongranted1, passthrough, depth sensing, mesh tracking
Meta Quest 2	✔️ Meta Browser	hand tracking, support for sessiongranted1, passthrough (black and white)
Meta Quest 1	✔️ Meta Browser	hand tracking, support for sessiongranted1
Meta Quest Pro	✔️ Meta Browser	hand tracking, support for sessiongranted1, passthrough
Pico Neo 4	✔️ Pico Browser	passthrough, hand tracking2
Pico Neo 3	✔️ Pico Browser	no hand tracking, inverted controller thumbsticks
Oculus Rift 1/2	✔️ Chrome
Valve Index	✔️ Chrome
HTC Vive	✔️ Chrome
Hololens 2	✔️ Edge	hand tracking, support for AR and VR (in VR mode, background is rendered as well)

Mobile Device	Browser	Notes
Android 10+	✔️ Chrome
Android 10+	✔️ Firefox
iOS 15+	(✔️)3 Safari (✔️)3 Chrome	No full code support, but Needle Everywhere Actions are supported for creating dynamic, interactive USDZ files.
iOS 15+	✔️ WebXR Viewer	browser is somewhat dated by now
Hololens 2	✔️ Edge
Hololens 1	❌	no WebXR support
Magic Leap 2	✔️
Magic Leap 1	✔️	deprecated device

Other Devices	Browser	Notes
Looking Glass Holographic Display	✔️ Chrome	requires Looking Glass bridge and some custom code, see our sample
Logitech MX Ink	✔️ Meta Browser	officially supported, see docs

1: Requires enabling a browser flag: chrome://flags/#webxr-navigation-permission 2: Requires enabling a toggle in the Developer settings 3: Uses Everywhere Actions or other approaches

VR, AR and QuickLook Examples

Visit our Needle Engine Samples to try many interactive examples right now. Or, try it live on your device by clicking the QR Code (for phones) or Open on Quest (for Meta Quest headsets) buttons below.

Adding VR and AR capabilities to a scene

AR, VR and networking capabilites in Needle Engine are designed to be modular. You can choose to not support any of them, or add only specific features.

Basic capabilities

1. Enable AR and VR Add a WebXR component. Optional: you can set a custom avatar by referencing an Avatar Prefab. By default, a basic DefaultAvatar is assigned.
2. Enable Teleportation Add a TeleportTarget component to object hierarchies that can be teleported on. To exclude specific objects, set their layer to IgnoreRaycasting.

Multiplayer

1. Enable Networking Add a SyncedRoom component.

2. Enable Desktop Viewer Sync Add a SyncedCamera component.

3. Enable Voice Chat Add a VoIP component.

:::tip Scene structure These components can be anywhere inside your hierarchy. They can also all be on the same GameObject, which is a common pattern. :::

Castle Builder uses all of the above for a cross-platform multiplayer sandbox experience. — #madebyneedle 💚

Special AR Components

1. Define the AR Session root and scale Add a WebARSessionRoot component to your root object. For AR experiences, often you want to scale the scene to fit the real world.

2. Define the user scale to shrink (< 1) or enlarge (> 1) the user in relation to the scene when entering AR.

Controlling object display for XR

1. Define whether an object is visible in Browser, AR, VR, First Person, Third Person Add a XR Flag component to the object you want to control.

2. Change options on the dropdown as needed. Common usecases are

   • hiding floors when entering AR

   • hiding Avatar parts in First or Third Person views. For example, in first-person view a person shouldn't be able to see their own head model.

Travelling between VR worlds

Needle Engine supports the sessiongranted state. This allows users to seamlessly traverse between WebXR applications without leaving an immersive session – they stay in VR or AR.

Currently, this is only supported on Oculus Quest 1, 2 and 3 in the Oculus Browser. On other platforms, users will be kicked out of their current immersive session and have to enter VR again on the new page. Requires enabling a browser flag: chrome://flags/#webxr-navigation-permission

• Click on objects to open links Add the OpenURL component that makes it very easy to build connected worlds.

Scripting

Read more about scripting for XR at the scripting XR documentation

Avatars

While we don't currently provide an out-of-the-box integration external avatar systems, you can create application-specific avatars or custom systems.

• Create a custom Avatar

  • Create an empty GameObject as avatar root

  • Add an object named Head and add a XRFlag that's set to Third Person

  • Add objects named HandLeft and HandRight

  • Add your graphics below these objects.

Experimental Avatar Components

There's a number of experimental components to build more expressive Avatars. At this point we recommended duplicating them to make your own variants, since they might be changed or removed at a later point.

Example Avatar Rig with basic neck model and limb constraints

• Random Player Colors As an example for avatar customization, you can add a PlayerColor component to your renderers. This randomized color is synchronized between players.

• Eye Rotation AvatarEyeLook_Rotation rotates GameObjects (eyes) to follow other avatars and a random target. This component is synchronized between players.

• Eye Blinking AvatarBlink_Simple randomly hides GameObjects (eyes) every few seconds, emulating a blink.

  Example Avatar Prefab hierarchy
• Offset Constraint OffsetConstraint allows to shift an object in relation to another one in Avatar space. This allows, for example, to have a Body follow the Head but keep rotation levelled. It also allows to construct simple neck models.

• Limb Constraint BasicIKConstraint is a very minimalistic constraint that takes two transforms and a hint. This is useful to construct simple arm or leg chains. As rotation is currently not properly implemented, arms and legs may need to be rotationally symmetric to "look right". It's called "Basic" for a reason!

HTML Content Overlays in AR

If you want to display different html content whether the client is using a regular browser or using AR or VR, you can just use a set of html classes. This is controlled via HTML element classes. For example, to make content appear on desktop and in AR add a <div class="desktop ar"> ... </div> inside the <needle-engine> tag:

<needle-engine>
    <div class="desktop ar" style="pointer-events:none;">
        <div class="positioning-container">
          <p>your content for AR and desktop goes here</p>
          <p class="only-in-ar">This will only be visible in AR</p>
        <div>
    </div>
</needle-engine>

Content Overlays are implemented using the optional dom-overlay feature which is usually supported on screen-based AR devices (phones, tablets).

Use the .ar-session-active class to show/hide specific content while in AR. The :xr-overlay pseudo class shouldn't be used at this point because using it breaks Mozilla's WebXR Viewer.

.only-in-ar {
  display: none;
}

.ar-session-active .only-in-ar {
  display:initial;
}

It's worth noting that the overlay element will be always displayed fullscreen while in XR, independent of styling that has been applied. If you want to align items differently, you should make a container inside the class="ar" element.

Augmented Reality and WebXR on iOS

Augmented Reality experiences on iOS are somewhat limited, due to Apple currently not supporting WebXR on iOS devices.

Needle Engine's Everywhere Actions are designed to fill that gap, bringing automatic interactive capabilities to iOS devices for scenes composed of specific components. They support a subset of the functionality that's available in WebXR, for example spatial audio, image tracking, animations, and more. See the docs for more information.

:::tip Limited custom code support in QuickLook Apple has strong limitations in place what kind of content can be used in QuickLook. Thus, custom script components can not automatically be converted for use in AR on iOS. You can add support for some sorts of custom code using our Everywhere Actions API. :::

Musical Instrument – WebXR and QuickLook support

Here's an example for a musical instrument that uses Everywhere Actions and thus works in browsers and in AR on iOS devices. It uses spatial audio, animation, and tap interactions.

Everywhere Actions and other options for iOS AR

There's also other options for guiding iOS users to even more capable interactive AR experiences:

1. Exporting content on-the-fly as USDZ files. These files can be displayed on iOS devices in AR. When exported from scenes with Everywhere Actions the interactivity is the same, more than sufficient for product configurators, narrative experiences and similar. An example is Castle Builder where creations (not the live session) can be viewed in AR.

Encryption in Space uses this approach. Players can collaboratively place text into the scene on their screens and then view the results in AR on iOS. On Android, they can also interact right in WebXR. — #madewithneedle by Katja Rempel 💚

1. Guiding users towards WebXR-compatible browsers on iOS. Depending on your target audience, you can guide users on iOS towards for example Mozilla's WebXR Viewer to experience AR on iOS.
2. Using camera access and custom algorithms on iOS devices. One can request camera image access and run custom algorithms to determine device pose. While we currently don't provide built-in components for this, here's a few references to libraries and frameworks that we want to try in the future:

   • AR.js (open source)

     • Experimental AR.js integration by FireDragonGameStudio
   • Mind AR (open source)
   • 8th Wall (commercial)

Image Tracking

Needle Engine supports WebXR Image Tracking (Live Demo) on Android and QuickLook Image Tracking on iOS.

You can find additional documentation in the Everywhere Actions section.

:::warning WebXR Image Tracking is still in a "draft" phase and not generally available So far, browser vendors haven't been able to agree on the final image tracking API for WebXR. As long as the specification is in "draft" phase (Marker Tracking Explainer), you and your app's users need to follow these steps to enable WebXR ImageTracking on Android devices:

1. Visit chrome://flags on your Android Chrome browser

2. Find and enable the WebXR Incubations option :::

Without that spec, one can still request camera image access and run custom algorithms to determine device pose. The downside is that users will have to accept additional permissions like camera access, and the tracking will not be as accurate as with the native capabilities of the device.

Here are some libraries to add image tracking based on camera access and local computer vision algorithms:

• Experimental AR.js integration with Needle Engine by FireDragonGameStudio
• AR.js (open source)
• Mind AR (open source)

References

WebXR Device API caniuse: WebXR Apple's Preliminary USD Behaviours