By schoen
on Tue, 01/08/2013 - 22:56
Hi there, I'm working on an app using the Qualcom Vuforia library, and I've had a couple of snags. I've used the v1 and v2 libraries in Unity 3 and 4 and have found the following issues. I'm not sure if this is something I'm doing wrong, or just standard issues with AR. First of all, the library is great. It works really well and is pretty straightforward to use/extend. I found, however, that the base version really needs the added damping code that can be found on the forum. In fact, my client and I weren't happy with the way that that code smoothed things out, so I created my own method, which I'd be happy to share. Either way, once the damping is added, the solution works really well 95% of the time. Our particular implementation involves using a 3D depth-based mask to mask out the 3D scene where the tracker object should be, to give the appearance that the tracker object is actually in the 3D scene. This obviously puts really heavy demands on the ability to precisely match the position of the tracker in the scene. The damping actually is a detriment here because while it is "catching up," the mask doesn't exactly overlap the real-world object, and the illusion is broken. Also, the trackers are mounted on the front of the object, not the top. Some are at an angle, some are vertical. I've found that we have more issues with the vertically-mounted trackers, even when looking at them dead-on. Either way, it was exceedingly difficult to size/position the scene/tracker so that the two objects matched up perfectly. I'm rather confident at this point that our mask model is correct. It seems that every time you track an object, some different offset is introduced, which we can't account for with a statically-placed scene. Aside from that issue, we've found that in certain orientations, the library will spit out transformations that "flip" the scene along an axis, not by 90 degrees but by some half angle. The scene keeps tracking this way until a different angle is reached and it flips back. Likewise, there is a lot of "noise" when holding the camera more-or-less in the same location, which seems to essentially pop back and forth between two rotations. I was wondering if anyone else has run into these issues or if there is something I'm doing differently. Thanks!
Sketchy tracking with the Unity plugin
bump
Sketchy tracking with the Unity plugin
Can you send me an example a/o some screen grabs of your project?
Are your targets configured as a MultiTarget?
Sketchy tracking with the Unity plugin
Thanks for the reply.
The targets are not MultiTarget. I have simultaneous targets set to 1, and there are 5 possible targets. I can't exactly bring the model closer because the model is actually a whole scene (not my idea).
Sketchy tracking with the Unity plugin
Try bringing the targets into a MT configuration if you can.
And post, or PM, a link to any video you have.
Sketchy tracking with the Unity plugin
Hey there,
Sketchy tracking with the Unity plugin
@schoen,
Have a look at UCS. It is a replacement for MultiTargets (amongst other things) and you can place the markers in any configuration you want. I will release a version supporting Vuforia 2.0 soon.
Sketchy tracking with the Unity plugin
Hi,
I'm also experiencing the 'jittering' and the 'flipping'.
Regarding the jittering; it seems like some kind of noise but when I use a still image I got the same problem as well.
Sketchy tracking with the Unity plugin
Sketchy tracking with the Unity plugin
Thanks for your reaction.
Probably you're right because I'm using a fairly small tracker too. However, I cannot use a bigger tracker so I was also working on similar solutions as you suggested.
Jittering issue
Hi there,
I am making a project using this awesum unity vuforia library, it is working great on the smaller image targets provided by vuforia,
But it starts jerking once I use the Big Images of those Image Targets ?? How should i tackle this issue ? Any help
Sketchy tracking with the Unity plugin
Hi there,
From what I understand with tracker size, the bigger the better. How detailed is your tracker image? The more features that the camera can identify, the better the tracking.
Sketchy tracking with the Unity plugin
Hi,
My tracker image size is around 1900 x 1200, with alot of trackable objects for camera to detect.
Sketchy tracking with the Unity plugin
Hm. It's been a while since I've worked with the library, so my info might be out of date. Does the tracker creation software still give you a "rating" for your tracker image?
Sketchy tracking with the Unity plugin
Hmmm, thanks I will look into it, but in the meantime do you have any demo implemented with multi-tracker detection .. It will be great help.
Sketchy tracking with the Unity plugin
Sorry, I have nothing at hand. The project I was using multi-tracker for was not mine to own. I'm pretty sure the documentation explains multi-tracker setup quite well. I didn't have any problems giving it a try.