Whilst learning about Reality Composer I found that it is possible to anchor an image using Reality Composer, meaning if I have an image in real life and a copy of it in the Reality Composer then using that I can build a whole scene right on top of the image. I was wondering, how does the actual anchoring happen?
I have worked before with SIFT keypoint matching, which could be used in this case as well, however, I cannot find how this works in Reality Composer.
The principle of operation is as simple as that:
Reality Composer's scene element called AnchorEntity contained in .rcproject file in RealityKit app conforms to HasAnchoring protocol. When RealityKit app's Artificial Intelligence sees any image thru rear camera, it compares it with the one containing inside reference image folder. If both images are identical, app creates an image-based anchor AnchorEntity (similar to ARImageAnchor in ARKit) that tethers its corresponding 3D model. Invisible anchor appears in the center of a picture.
AnchorEntity(.image(group: "ARResourceGroup", name: "imageBasedAnchor"))
When you're using image-based anchors in RealityKit apps, you're using a RealityKit's analog of ARImageTrackingConfig that is less processor intensive than ARWorldTrackingConfig.
The difference between AnchorEntity(.image) and ARImageAnchor is that RealityKit automatically tracks all its anchors, while ARKit uses renderer(...) or session(...) methods for updating.
Related
I am currently playing a bit with ARKit. My goal is to detect a shelf and draw stuff onto it.
I did already find the ARReferenceImage and that basically works for a very, very simple prototype, but the image needs to be quite complex it seems? Xcode always complains if I try to use something a lot simpler (like a QR-Code like image). With that marker I would know the position of an edge and then I'd know the physical size of my shelf and know how to place stuff into it. So that would be ok, but I think small and simple markers will not work, right?
But ideally I would not need a marker at all.
I know that I can detect e.g. planes, but I want to detect the shelf itself. But as my shelf is open, it's not really a plane. Are there other possibilities to find an object using ARKit?
I know that my question is very vague, but maybe somebody could point me in the right direction. Or tell me if that's even possible with ARKit or if I need other tools? Like Unity?
There are several different possibilities for positioning content in augmented reality. They are called content anchors, and they are all subclasses of the ARAnchor class.
Image anchor
Using an image anchor, you would stick your reference image on a pre-determined spot on the shelf and position your 3D content relative to it.
the image needs to be quite complex it seems? Xcode always complains if I try to use something a lot simpler (like a QR-Code like image)
That's correct. The image needs to have enough visual detail for ARKit to track it. Something like a simple black and white checkerboard pattern doesn't work very well. A complex image does.
Object anchor
Using object anchors, you scan the shape of a 3D object ahead of time and bundle this data file with your app. When a user uses the app, ARKit will try to recognise this object and if it does, you can position your 3D content relative to it. Apple has some sample code for this if you want to try it out quickly.
Manually creating an anchor
Another option would be to enable ARKit plane detection, and have the user tap a point on the horizontal shelf. Then you perform a raycast to get the 3D coordinate of this point.
You can create an ARAnchor object using this coordinate, and add it to the ARSession.
Then you can again position your content relative to the anchor.
You could also implement a drag gesture to let the user fine-tune the position along the shelf's plane.
Conclusion
Which one of these placement options is best for you depends on the use case of your app. I hope this answer was useful :)
References
There are a lot of informative WWDC videos about ARKit. You could start off by watching this one: https://developer.apple.com/videos/play/wwdc2018/610
It is absolutely possible. If you do this in swift or Unity depends entirely on what you are comfortable working in.
Arkit calls them https://developer.apple.com/documentation/arkit/arobjectanchor. In other implementations they are often called mesh or model targets.
This Youtube video shows what you want to do in swift.
But objects like a shelf might be hard to recognize since their content often changes.
I am working on a project that will display objects below the ground using AR Quick Look. However, the AR mode seems to bring everything above the ground based on the bounding box of the objects in the scene.
I have tried using the USDZ directly and composing a simple scene in Reality Composer with the object or with a simple cube with the exact same result. AR preview mode in Reality Composer is showing the object below the ground or below an image anchor correctly. However, if I export the scene as a .reality file and open it in using AR Quick Look, it brings the object above the ground as well.
Is there a way to achieve showing an object below the detected horizontal plane or image (horizontal) using AR Quick Look?
This is still an issue a year later. I have submitted feedback to Apple. I suggest you do too. I have suggested adding a checkbox to keep Y axis persistent. My assumption is this behaves this way to prevent the object from colliding with the ground, but I don't think it's necessary. It's just a limitation right now.
I'm trying to find the best strategy to align a SCNScene to a physical table. Just like the ARKit app WWWFreeRivers.
Currently I'm just testing out to map a simple plane model, with the same dimensions as the table. If I draw out the plane that ARKit detects, I can see that the plane is not very accurate with the edges. They always go outside of the edges (image below).
So I can't really rely on that plane, to just place the model in the center of this. The model is not rotated correctly either (image below).
I had another idea to use the ARReferenceImage technique, to take a picture of the table top texture, and let ARKit find and match this "image" of the table. But even with wood grain texture, it wasn't enough data for ARKit to recognize it. And ARKit just fails if you have these errors. It doesn't even try to do a bad match.
How can I go about doing this?
Ideas I've had so far:
Take image of table and use ARImageReference feature to match it. This didn't work. Maybe if I add some more interesting feature points to the table, like some sort of QR codes in the corners.
Detect the plane, and then tap the four corners on the table to map out a square, and use this.
Do as the WWW app, just place the object randomly on the plane, and then let the user scale, move and rotate the model to give it correct placement.
Any more ideas? What do you think will be the best approach to this?
Two options I can think of you could use.
You could create an ARWorldMap (iOS12+ only) and use it instead of the ARImageReference, walk around the area while creating a map that subsequent ARKit Sessions will remember. You can experiment slightly as to how to fit your models within the four corners of the table (this is slightly tedious w/o much help from the SceneView editor). However, when you load the saved ARWorldMap and localized against it (just like the ARImageReference), your model should fit within the four corners of the table every time.
If you use something like Unity (and its ARKit plugin), it has much more powerful Editor tools (3D viewer/designer). There are some tools that can help you save the map just like ARWorldMap but then bring in details of the map into the editor so you can line things up right really easily. Placenote's Spatial Capture toolkit can help here. Placenote (iOS11+) creates its own "World Map" but it exposes the visual details in the Unity editor, making it easier to line things up and then localize against (Example). The map is also stored on a managed cloud from the get-go to make sharing across phones much easier.
P.S: Both these options require you to keep the environment generally static (not large lighting changes etc.), though this was a similar constraint to when using ARIMageReference.
I'm starting to learn how to use ARkit and I would like to add a button like the one in the Pokemon go application where you can switch between AR ON (with a model into the real world) and AR OFF (without using a camera, having just the 3D model with a fixed background). Are there any easy way to do it?
Another good example of what you're asking about is the AR Quick Look feature in iOS 12 (see WWDC video or this article): when you quick look a USDZ file you get a generic white-background preview where you can spin the object around with touch gestures, and you can seamlessly switch back and forth between that and a real-world AR camera view.
You've asked about ARKit but not said anything about which renderer you're using. Remember, ARKit itself only tells you about the real world and provides live camera imagery, but it's up to you to display that image and whatever 3D overlay content you want — either by using a 3D graphics framework like SceneKit, Unity, or Unreal, or by creating your own renderer with Metal. So the rest of this answer is renderer-agnostic.
There are two main differences between an AR view and a non-AR 3D view of the same content:
An AR view displays the live camera feed in the background; a non-AR view doesn't.
3D graphics frameworks typically involve some notion of a virtual camera that determines your view of the 3D scene — by moving the camera, you change what part of the scene you see and what angle you see it from. In AR, the virtual camera is made to match the movement of the real device.
Hence, to switch between AR and non-AR 3D views of the same content, you just need to manipulate those differences in whatever way your renderer allows:
Hide the live camera feed. If your renderer lets you directly turn it off, do that. Otherwise you can put some foreground content in front of it, like an opaque skybox and/or a plane for your 3D models to rest on.
Directly control the camera yourself and/or provide touch/gesture controls for the user to manipulate the camera. If your renderer supports multiple cameras in the scene and choosing which one is currently used for rendering, you can keep and switch between the ARKit-managed camera and your own.
I am making an augmented reality App to demonstrate the options in MacBook and I used the Vuforia SDK.
Here is my problem:
1) I tried with Vuforia Sample Core Feature and I used Image Targets. In Image targets it gives only one image at a time. I attached the output in below mentioned image.
2) My expectation is to show multiple text or image while capturing the real MacBook like below mentioned image.
Please guide me to achieve this.
Vuforia iOS SDK is using OpenGL ES loading 3D object，which's unfriendly to use.
You can use Scenekit, put your objects in a scene, set a rectangle node, put the model in four corners of a rectangle.When ImageTrack is success, load your scene.
How to use SceneKit in Vuforia? check this:https://github.com/yshrkt/VuforiaSampleSwift