Supported Devices

Theoretically all WebXR-capable devices and browsers should be supported. That being said, we've tested the following configurations:

Tested VR Device	Browser	Notes
Meta Quest 1	✔️ Meta Browser	hand tracking, support for sessiongranted1
Meta Quest 2	✔️ Meta Browser	hand tracking, support for sessiongranted1, passthrough (black and white)
Meta Quest Pro	✔️ Meta Browser	hand tracking, support for sessiongranted1, passthrough
Pico Neo 3	✔️ Pico Browser	no hand tracking, inverted controller thumbsticks
Pico Neo 4	✔️ Pico Browser	passthrough, hand tracking2
Oculus Rift 1/2	✔️ Chrome
Hololens 2	✔️ Edge	hand tracking, support for AR and VR (in VR mode, background is rendered as well)
Meta Quest 1/2 via Oculus Link	✔️ Chrome	no hand tracking, known issues with repeated refresh of a WebXR session in Chrome
Looking Glass Portrait	✔️ Chrome	requires shim, see samples

Tested AR Device	Browser	Notes
Android 10+	✔️ Chrome
Android 10+	✔️ Firefox
iOS 15+	✔️ WebXR Viewer	does not fully implement standards, but supported
iOS 15+	(✔️)3 Safari	No full code support, but Needle Everywhere Actions are supported for creating dynamic, interactive USDZ files.
Hololens 2	✔️ Edge
Hololens 1	❌	no WebXR support
Magic Leap 2	✔️

Not Tested but Should Work™️	Browser	Notes
Magic Leap 1		please let us know if you tried!

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

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

• Enable AR and VR
  Add a WebXR component.
  Optional: you can set a custom avatar by referencing an Avatar Prefab.
  By default a very basic DefaultAvatar is assigned.

• Enable Teleportation
  Add a TeleportTarget component to object hierarchies that can be teleported on.
  To exclude specific objects, set their layer to IgnoreRaycasting.

• Enable going into Miniature Mode
  Pointing onto a surface and pressing on a controller switches between 1:10 scale (miniature mode) and 1:1 scale.
  We're planning to add a component to have more control over this functionality.

Multiplayer

• Enable Networking
  Add a SyncedRoom component.

• Enable Desktop Viewer Sync
  Add a SyncedCamera component.

• Enable XR Avatar Sync
  Add a WebXRSync component.

• Enable Voice Chat
  Add a VoIP component.

Note: these components can be anywhere inside your GltfObject hierarchy. They can also all be on the same GameObject.

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

Special AR Components

• Define the AR Session Root and Scale
  Add a WebARSessionRoot component to your root object.
  Here you can 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

• 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. Change options on the dropdown as needed.

  Common usecases are

  • hiding floors when entering AR
  • hiding Avatar parts in First or Third Person views (e.g. first-person head shouldn't be visible).

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 and 2 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
  The samples repository contains a small script ClickToOpenWebsite that makes it very easy to build connected worlds.

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.

Image Tracking

WebXR ImageTracking is still in "draft" phase: Marker Tracking Explainer
But you can still use WebXR ImageTracking with Needle Engine today:

• Enable WebXR Incubations in chrome
• Add the WebXRImageTracking component

You can find additional documentation in the Everywhere Actions section

Without that spec, one can still request camera image access and run custom algorithms to determine device pose.
Libraries to add image tracking:

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

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.

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:

3. 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)

References

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