I have made an application for the hololens with the holotoolkit. The app gets an array with 3D positions and spawns GameObjects based on these positions.
After walking a bit in the room and change some realworld objects (maybe open a door or something) the hololens will recognized it, then a window opens and says 'Finding your space' and all of the GameObjects are in the wrong position.
How can I use SpaitalMapping, but not allow to replace the GameObjects i place?
After walking a bit in the room and change some realworld objects (maybe open a door or something) the hololens will recognized it
I'm not sure the details of the changes you made on realworld objects, but some changes in the real world may have a great impact on the lighting conditions. For example, after opening an outward door in a dimly lit room. a lot of daylight will enter the room.
Lighting can make a difference in the visual features that HoloLens detects. So changeable lighting conditions might cause HoloLens to lose tracking.
Besides, in environments where the visual features change because most objects move, will also cause the same problem.
I recommend that you try the steps in I see a message that says Finding your space to fix this problem. In short, make sure your artificial lighting conditions and WiFi signal are stable and try moving more slowly.
Related
I can't share much code because it's proprietary, but this is a bug that's been haunting me for awhile. We have SceneKit geometry added to the ARKit face node and displayed inside an ARSCNView. It works perfectly almost all of the time, but about 1 in 100 times, nothing shows up at all. The ARSession is running, and none of the parent nodes are set to hidden. Further, when I look at Debug Memory Graph function in Xcode, the geometry appears to be entirely visible there (and doesn't seem to be set to hidden). I can see all the nodes attached to the face node perfectly within the ARSCNView of the memory graph, but on the screen, nothing shows up. This has been an issue for multiple iOS versions, so it didn't just appear with a recent update.
Has anybody run into a similar problem, or does anybody have any ideas to look into? Is it an apple bug, or is there a timing issue I might not be aware of? It's been really hard to debug because of how infrequent it is, and I haven't found it discussed on any other forums (but point me in the right direction if there is a previous discussion). Thanks!
This is pretty common practice if AR tracking is poor for some reason.
I ran into a similar problem too. I think it's definitely a tracking error which arises due to the fault of the user of AR app. Sometimes, if you're using World Tracking Config in ARKit and track a surrounding environment offhandedly or if you are tracking under inappropriate conditions – you get a sloppy tracking data which results in situation when your World Grid/Axis may be unpredictably shifted aside and your model may fly away somewhere. If such a situation arises - look for your model somewhere nearby – maybe it’s behind you.
If you're using a gadget with a LiDAR, the aforementioned situation is almost impossible, but if you're using a gadget with no LiDAR you need thoroughly track your room. Also there must be good lighting conditions and high-contrast real-world objects with distinguishable non-repetitive textures.
I'm working on an application where the concept is that you can 'select' objects before actually placing them. So what I wanted to do was have some low quality objects on a shelf or something like it. When the user selects the object he then can tap to place the high quality version of the object in his area for further viewing.
I was wondering if it's possible with vuforia. I wanted to use this platform since it works well from what I could tell and it's cross platform (The application needs to be for android and the HoloLens).
I have set up the basic application where you can place a capsule in the area. Now I wanted to automatically place the (in this case capsule) once vuforia has detected a ground plane. From what I could see the plane finder has events that go off when an input is detected, but I couldn't find an event that goes off when the ground plane is detected. Is it still possible with vuforia? I know it's doable with the HoloLens, but I would like to know if it's possible for android or other mobile devices. I really don't know where to start/look for so I hope someone can point me in the right direction.
Let me know if I need to include more information!
The Vuforia PlaneFinderBehaviour (see doc here) has the event OnAutomaticHitTest which fires every frame a ground plane is detected.
So you can use it to automatically spawn an object.
You have to add your method in the On Automatic Hit Test instead of the On Interactive Hit Test list of the "Plane Finder":
I've heard that vuforia fusion, does not yet support ARCore (it supports ARKit) so it uses an internal implementation to simulate ARCore functionality, and they are waiting for a final release of ARCore to support it. Many users reported that their objects move even when they use an ARCore supported device.
I'm making a game in ROBLOX, which has a cutscene in it at the start. At the end of the cutscene, the camera zooms up on the character and you spawn in. However, when I spawn in, I can see the dummy I used for the cutscene, so how after a certain interval can you make that dummy disappear?
Does the dummy just need to become invisible? If so, every physical object in ROBLOX (or more formally Part) has a .Transparency field that spans from 0 (for no transparency) to 1 (for full transparency, or in other words, invisible). I don't know what your "dummy" looks like in the object hierarchy, but let's say your dummy were a Model located at workspace.dummy, and that it has a head, torso, left arm, etc. located at workspace.dummy.Head, workspace.dummy.Torso, workspace.dummy.LeftArm, etc. To make the Parts of the dummy invisible, you would have code that looks like this:
workspace.dummy.Head.Transparency = 1
workspace.dummy.Torso.Transparency = 1
workspace.dummy.LeftArm.Transparency = 1
...
And so on. This, however, will make the dummy invisible to all players. If you are making a single-player game, this will not matter; however, if it is a multiplayer game, then this could be a problem. Making the dummy non-transparent again to do the cutscene for a new player would make the dummy visible to all players. If this is a problem for you, there are two things you could do that I know of:
The first and easiest way would be to just have the cutscene take place at a location very far away from where your game occurs; for example, you could shift everything in your cutscene 10,000 studs in the X direction. This would ensure the objects in the cutscene would be out of the render distance of the players playing the actual game, so only the players whose cameras are being manipulated to carry out the cutscene would see it.
The second, more complicated, and not future-proof option involves a very useful bug that is frequently taken advantage of but subject to being fixed at any time since it is not an official feature. This bug is the exploitation of a Camera (or less commonly a Message, which is deprecated) to create what are called local parts—Parts only visible to a certain player. How to create local parts and discussion of benefits and consequences of using local parts is a little complicated and beyond the scope of this answer. Go here if you'd like to learn more. Taken directly from the ROBLOX Wiki at the time of writing:
Local parts are in no way supported by Roblox. They exploit unspecified replication behaviour - at any given moment, the development team could release an update that changes how Camera and Message instances behave, preventing you from making local parts.
I am considering developing an ARKit app, but before deciding to buy an iPhone I would like to ask two questions that are crucial for me. Please let me know if this has already been asked, as I could not find it somewhere else online.
The questions:
1. Let's say the motion tracking gets lost (e.g., when pointing to a white wall) and then recovers again. Does it localize in the same frame of reference or it starts from scratch? Also, are the anchors preserved?
2. Let's say I pause the session and then run it again (e.g., by leaving the app and then coming back). Does is localize back to the frame of reference from before the pause? Also, are the anchors preserved?
I am asking this because I know that localization does not work in ARCore yet and I was wondering about its state in ARKit.
Thanks!
ARKit has two or three ways to lose tracking (depending on how you think of them); each has a different effect on anchors.
1. TemporARy tracking quality issues
(I honestly fumbled caps lock in the middle of that word. My keyboard is making the puns for me!)
In the first situation you mention, and similar cases — pointing at a blank wall, giving the phone a sudden jostle, moving from a darkened area into bright light or vice versa — your app will get notified of changes to ARKit’s tracking state that effect the quality of camera pose tracking.
When the tracking state is limited, ARKit’s idea of where the world is might be out of sync with the real world, but it still has enough information to be able to relocalize when the situation passes. That includes anchors. (Try for yourself; run one of Apple’s ARKit sample code projects, and cover the camera lens for a bit while moving the phone.)
If whatever situation is affecting the tracking state persists for a long time, relocalization is unlikely to succeed. It can help to track how long you’ve been in limited tracking and offer the user a way to restart the session if things get too out of whack.
2 and 3. Session interruption and resume or restart
If something happens that interrupts ARKit’s ability to receive camera and motion data — like the incoming phone call screen on iPhone, or the user responding to an interactive notification, your app gets a sessionWasInterrupted message. There’s nothing you can do in this case (as far as session management is concerned) other than wait for a corresponding sessionInterruptionEnded message.
If the interruption was brief and the device hasn’t moved much since, there’s a chance of automatic relocalization. Of course, you can’t tell how much the device has been moved because motion tracking was off... you can make an educated guess based on the duration of interruption and how sensitive your AR experience is to tracking precision, and decide accordingly whether to restart the session. (For example, a game that has space invaders floating in the air is less affected than an app that lets the user trace out a floor plan by marking walls.)
Aside: Traditional iOS UI patterns like modal view controllers, tab views, and navigation controllers can push the view hosting an AR session away, interrupting the session and losing tracking. Like Apple’s Human Interface Guidelines for AR suggest, it can be good to use things like popover views instead, so that you keep the AR experience onscreen and the session running.
When/if you do restart your AR session, you have a choice of whether to keep anchors or reset tracking. If you’ve already lost localization, what this really means is whether you keep track of anchors in arbitrary coordinate space they’re defined in (even though that space doesn’t line up with the real world anymore), or just lose all the anchors.
Short of restarting the session, though, there’s nothing that’ll cause anchors to be removed. And if you lose tracking temporarily enough to get relocalization, anchors that track real-world objects (that is, plane anchors, as opposed to the ones you manually create) should adjust back to realistic positions even if the coordinate systems doesn’t quite line up the way it used to.
I am working on an iOS app with tracking. I have implemented Kalman smoothing in order to present a pleasing path. This is working pretty well at this point.
I am having a bit of trouble dealing with the user-not-moving case though. When the user IS moving we get very good reads back from the CLLocation Manager. And even when a reading is a bit off the Kalman algorithm takes care of it.
When standing still the CLLocation Manager delegate is still receiving "accurate" locations. They have good accuracy, not an unbelievable speed. Looking at the screen with human eyes it's clear that the user is standing still with all these points just scattered around. Some points very close and a few of them far out.
I have tried setting the CLLocationManager property pausesLocationUpdatesAutomatically but it doesn't seem to be working that well. It doesn't always stop when it should and there have been difficulty restarting the tracking again as the antennas are powered down.
So I'm looking to keep the tracking on the whole time but I want to filter out the jitter in post processing. So I determine programmatically that the user is stopped and discard (or ignore) all locations until the user is moving again.
I'm not really sure how to go about this, what algorithm is appropriate to achieve something like this?