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3D Objects sliding on printed marker

By Mrvn on Thu, 01/18/2018 - 14:25

Hi there,

i got a problem where the 3D Objects are sliding away from the marker when I move my device (iPad Pro 12,9"). I created a new Project and positioned (snap) some primitives of Unity at the edges of a standard Vuforia marker (Image target, stones). I built it onto the iPad and look straight at the marker everything seems to be ok, but when i move a few steps away from the marker, to see all objects, the objects are not at the correct position anymore(around 2-4cm difference). Eventhough when i move around the marker, the objects are always displaced in a weird direction, which is not always the same. By tilting the iPad (left and right), the objects are moving to the opposite side than the tilt.

I also tried it on several iPhones, iPads and Android devices. My expectation is that the objects are still placed at the edges of the marker, but they are kind of sliding "away".

I use Unity3D 2017.3 and the integrated Version of Vuforia 7. I also tried some other settings in the Vuforia configuration but the problem is still there. In my Project i need to use the Extended Tracking, but the wrong positioning without, is there too.

What I've tried:

  • using another marker
  • creating a new project
  • use another device
  • World Center mode changed
  • Extended tracking on/off
  • Camera optimization (speed/quality)

My guess is, it could have something to do with the projection matrix or the intrinsic parameters of the camera. Maybe someone can help me.

Thanks in advance!

This doesn't sound normal.  With extending tracking on, maybe, but with it off it should be pretty solid.  Have you tried the Vuforia sample project?  Also, a link to a video might help figure out what is going on.
 

martejpad

Fri, 01/19/2018 - 11:02

Permalink

Hello both,

I posted a new thread last night about a similar problem but it seems it hasn't been approved yet as it doesn't appear on the forum.

Here's the video: https://drive.google.com/open?id=11R7qnPNob6zs0Vv5apF_d2PoZhqq_DNh

Please notice:

1) how the cube aligned on top of the N letter of "OXYGEN" is sliding around. Second 22 of the video is a good example.

Hi martejpad,

thanks for your reply.

It seems that you've got the same problem. I can't mention some "black stripes" on restarting the app. Maybe you can post a screenshot? Or is it just for one frame? 

Thanks Mrvn!

Yesterday I noticed that when these black strips appear the starting position of the cube (before moving the camera around and the sliding happening) is correct. Here are a couple of screenshots to illustrate what I mean:

Hi martejpad,

actually I don't see those black strips you mentioned.

Have you made any progress or did you find something new?

Thanks!

Hi martejpad,

we've gained a new insight.

Is your app on something other than "Auto Rotation" in the Player Settings?

No response from anyone at Vuforia in this thread and want to make sure someone sees it.  Consider posting a summary of your findings or a link to this post in the Bugs section of the forum so this post isn't missed.