A-Frame's immersive-ar functionality will work on some Android devices I've tested with, but I haven't had success with iOS.
It is possible to use an A-Frame scene for markerless AR on iOS using a commercial external library. Example: this demo from Zapworks using their A-Frame SDK. https://zappar-xr.github.io/aframe-example-instant-tracking-3d-model/
The tracking seems to be no where near as good as A-Frame's hit test demo (https://github.com/stspanho/aframe-hit-test), but it does seem to work on virtually any device and browser I've tried, and it is good enough for the intended purpose.
I would be more than happy to fallback to lower quality AR mode in order to have AR at all in devices that don't support immersive-ar in browser. I have not been able to find an A-Frame compatible solution for using only free/open source components for doing this, only commercial products like Zapworks and 8th Wall.
Is there a free / open source plugin for A-Frame that allows a scene to be rendered with markerless AR across a very broad range of devices, similar to Zapworks?
I ended up rolling my own solution which wasn't complete, but good enough for the project. Strictly speaking, there's three problems to overcome with getting a markerless AR experience on mobile without relying on WebXR:
Webcam display
Orientation
Position
Webcam display is fairly trivial to implement in HTML5 without any libraries.
Orientation is already handled nicely by A-FRAME's "magic window" functionality, including on iOS.
Position was tricky and I wasn't able to solve it. I attempted to use the FULLTILT library's accelerometer functions, and even using the readings with gravity filtered out I wasn't able to get a high enough level of accuracy. (It happened that this particular project did not need it)
I have problems in myself when I drive cars 🚘 I forget to slowly in some way have cameras 🎥 speed in high ways so I thinked if possible to make IOS APP to fixing these problems I explain my thing in image but I can't convert to coding by this step ?
1-After to speed camera 🎥 100 Miter Alerts me app( (there are camera speeds pleas slow down your speed.))
2- just post code i have basic programming languages in swift.
I'm not sure if I got you wright, so please correct me if I'm wrong.
You want an iOS app that tells you if there is a speed camera on the road you're driving, right?
So you have some possibilities to achieve that:
you can have a look at the app store. There are lot of such apps (e.g. TomTom) (easiest way)
if you want to build your own app you can make a use of the navigation sdk provided by mapbox: https://www.mapbox.com/help/ios-navigation-sdk/ (some programming skills needed)
Build your own app from scratch (much work and advanced programming skills)
If you want to build your app by mapbox or on your own you'll need the GPS-locations of speed cameras like provided here: https://www.scdb.info/
What is the best way, if any, to use Apple's new ARKit with multiple users/devices?
It seems that each devices gets its own scene understanding individually. My best guess so far is to use raw features points positions and try to match them across devices to glue together the different points of views since ARKit doesn't offer any absolute referential reference.
===Edit1, Things I've tried===
1) Feature points
I've played around and with the exposed raw features points and I'm now convinced that in their current state they are a dead end:
they are not raw feature points, they only expose positions but none of the attributes typically found in tracked feature points
their instantiation doesn't carry over from frame to frame, nor are the positions exactly the same
it often happens that reported feature points change by a lot when the camera input is almost not changing, with either a lot appearing or disappearing.
So overall I think it's unreasonable to try to use them in some meaningful way, not being able to make any kind of good point matching within one device, let alone several.
Alternative would to implement my own feature point detection and matching, but that'd be more replacing ARKit than leveraging it.
2) QR code
As #Rickster suggested, I've also tried identifying an easily identifiable object like a QR code and getting the relative referential change from that fixed point (see this question) It's a bit difficult and implied me using some openCV to estimate camera pose. But more importantly very limiting
As some newer answers have added, multiuser AR is a headline feature of ARKit 2 (aka ARKit on iOS 12). The WWDC18 talk on ARKit 2 has a nice overview, and Apple has two developer sample code projects to help you get started: a basic example that just gets 2+ devices into a shared experience, and SwiftShot, a real multiplayer game built for AR.
The major points:
ARWorldMap wraps up everything ARKit knows about the local environment into a serializable object, so you can save it for later or send it to another device. In the latter case, "relocalizing" to a world map saved by another device in the same local environment gives both devices the same frame of reference (world coordinate system).
Use the networking technology of your choice to send the ARWorldMap between devices: AirDrop, cloud shares, carrier pigeon, etc all work, but Apple's Multipeer Connectivity framework is one good, easy, and secure option, so it's what Apple uses in their example projects.
All of this gives you only the basis for creating a shared experience — multiple copies on your app on multiple devices all using a world coordinate system that lines up with the same real-world environment. That's all you need to get multiple users experiencing the same static AR content, but if you want them to interact in AR, you'll need to use your favorite networking technology some more.
Apple's basic multiuser AR demo shows encoding an ARAnchor
and sending it to peers, so that one user can tap to place a 3D
model in the world and all others can see it. The SwiftShot game example builds a whole networking protocol so that all users get the same gameplay actions (like firing slingshots at each other) and synchronized physics results (like blocks falling down after being struck). Both use Multipeer Connectivity.
(BTW, the second and third points above are where you get the "2 to 6" figure from #andy's answer — there's no limit on the ARKit side, because ARKit has no idea how many people may have received the world map you saved. However, Multipeer Connectivity has an 8 peer limit. And whatever game / app / experience you build on top of this may have latency / performance scaling issues as you add more peers, but that depends on your technology and design.)
Original answer below for historical interest...
This seems to be an area of active research in the iOS developer community — I met several teams trying to figure it out at WWDC last week, and nobody had even begun to crack it yet. So I'm not sure there's a "best way" yet, if even a feasible way at all.
Feature points are positioned relative to the session, and aren't individually identified, so I'd imagine correlating them between multiple users would be tricky.
The session alignment mode gravityAndHeading might prove helpful: that fixes all the directions to a (presumed/estimated to be) absolute reference frame, but positions are still relative to where the device was when the session started. If you could find a way to relate that position to something absolute — a lat/long, or an iBeacon maybe — and do so reliably, with enough precision... Well, then you'd not only have a reference frame that could be shared by multiple users, you'd also have the main ingredients for location based AR. (You know, like a floating virtual arrow that says turn right there to get to Gate A113 at the airport, or whatever.)
Another avenue I've heard discussed is image analysis. If you could place some real markers — easily machine recognizable things like QR codes — in view of multiple users, you could maybe use some form of object recognition or tracking (a ML model, perhaps?) to precisely identify the markers' positions and orientations relative to each user, and work back from there to calculate a shared frame of reference. Dunno how feasible that might be. (But if you go that route, or similar, note that ARKit exposes a pixel buffer for each captured camera frame.)
Good luck!
Now, after releasing ARKit 2.0 at WWDC 2018, it's possible to make games for 2....6 users.
For this, you need to use ARWorldMap class. By saving world maps and using them to start new sessions, your iOS application can now add new Augmented Reality capabilities: multiuser and persistent AR experiences.
AR Multiuser experiences. Now you may create a shared frame of a reference by sending archived ARWorldMap objects to a nearby iPhone or iPad. With several devices simultaneously tracking the same world map, you may build an experience where all users (up to 6) can share and see the same virtual 3D content (use Pixar's USDZ file format for 3D in Xcode 10+ and iOS 12+).
session.getCurrentWorldMap { worldMap, error in
guard let worldMap = worldMap else {
showAlert(error)
return
}
}
let configuration = ARWorldTrackingConfiguration()
configuration.initialWorldMap = worldMap
session.run(configuration)
AR Persistent experiences. If you save a world map and then your iOS application becomes inactive, you can easily restore it in the next launch of app and in the same physical environment. You can use ARAnchors from the resumed world map to place the same virtual 3D content (in USDZ or DAE format) at the same positions from the previous saved session.
Not bulletproof answers more like workarounds but maybe you'll find these helpful.
All assume the players are in the same place.
DIY ARKit sets up it's world coordinate system quickly after the AR session has been started. So if you can have all players, one after another, put and align their devices to the same physical location and let them start the session there, there you go. Imagine the inside edges of an L square ruler fixed to whatever available. Or any flat surface with a hole: hold phone agains surface looking through the hole with camera, (re)init session.
Medium Save the player aligning phone manually, instead detect a real world marker with image analysis just like #Rickster described.
Involved Train an Core ML model to recognize iPhones and iPads and their camera location. Like it's done with human face and eyes. Aggregate data on a server, then turn off ML to save power. Note: make sure your model is cover-proof. :)
I'm in the process of updating my game controller framework (https://github.com/robreuss/VirtualGameController) to support a shared controller capability, so all devices would receive input from the control elements on the screens of all devices. The purpose of this enhancement is to support ARKit-based multiplayer functionality. I'm assuming developers will use the first approach mentioned by diviaki, where the general positioning of the virtual space is defined by starting the session on each device from a common point in physical space, a shared reference, and specifically I have in mind being on opposite sides of a table. All the devices would launch the game at the same time and utilize a common coordinate space relative to physical size, and using the inputs from all the controllers, the game would remain theoretically in sync on all devices. Still testing. The obvious potential problem is latency or disruption in the network and the sync falls apart, and it would be difficult to recover except by restarting the game. The approach and framework may work for some types of games fairly well - for example, straightforward arcade-style games, but certainly not for many others - for example, any game with significant randomness that cannot be coordinated across devices.
This is a hugely difficult problem - the most prominent startup that is working on it is 6D.ai.
"Multiplayer AR" is the same problem as persistent SLAM, where you need to position yourself in a map that you may not have built yourself. It is the problem that most self driving car companies are actively working on.
I have been working Augmented Reality for quite a few months. I have used third party tools like Unity/Vuforia to create augmented reality applications for android.
I would like to create my own framework in which I will create my own AR apps. Can someone guide me to right tutorials/links to achieve my target. On a higher level, my plan is to create an application which can recognize multiple markers and match it with cloud stored models.
That seems like a massive undertaking: model recognition is not an easy task. I recommend looking at OpenCV (which has some standard algorithms you can use as a starting point) and then looking at a good computer vision book (e.g., Richard Szeliski's book or Hartley and Zisserman).
But you are going to run into a host of practical problems. Consider that systems like Vuforia provide camera calibration data for most Android devices, and it's hard to do computer vision without it. Then, of course, there's efficiently managing the whole pipeline which (again) companies like Qualcomm and Metaio invest huge amounts of $$ in.
I'm working on a project that does framemarker tracking and I've started exporting bits of it out to a project I'm calling OpenAR. Right now I'm in the process of pulling out unpublishable pieces and making Vuforia and the OpenCV versions of marker tracking interchangeable. You're certainly welcome to check out the work as it progresses. You can see videos of some of the early work on my YouTube channel.
The hard work is improving performance to be as good as Vuforia.
Now I have an requirement in Augmented Reality, I suppose to detect the live object(pen/marker) then I have play some interactive content.
I need a suggestion/advise from you is to recommend the appropriate SDK to develop this app.
I used Vuforia for normal/simple AR app but this is involved the real time object detection.
Friends, kindly suggest me the SDK to meet the requirement.
-Murali Krishnan
You can do this with a cylinder object. you would need to create a different object, for each pen style you would want as a trackable.
https://developer.vuforia.com/resources/dev-guide/creating-cylinder-target
As mentioned by ashatte, you should have a look at metaios sdk.
You are looking for 3d Markerless tracking. The sdk is very good for this.