"We offer new support options and therefor the forums are now in read-only mode! Please check out our Support Center for more information." - Vuforia Engine Team

Weird floating / double transforms behaviour with model target (iOS, 8.3.8, 2019.1.4f)

By R42Interactive on Fri, 08/16/2019 - 18:40

I have a model target setup which works fine tracking-wise, but when I move the device I get this weird floating effect, kind of looks like an extra transform applied to the mesh, almost as if it wanted to stick to the center of the device like if AR was not enabled.

You can see a video of the issue here: https://drive.google.com/open?id=1B3yp2Urr2EaAY0I9QC6-iff-3pv72aVo

This is using Unity 2019.1.4f, with Vuforia 8.3.8 (before I was using Unity's built-in 8.1.0 version and still having the same issue, tried updating but with no success) on a iPad mini 2019 (tried an iPad pro as well, no luck)

Things I've already tried and didn't make a difference:

  • Ensure the device's positional tracking is on
  • Tested with both trained and non-trained targets
  • Tested on different orientations
  • Tested on different platforms (same issues appear using a webcam on a Windows machine)
  • Updating to the last Unity version (2019.1.14f)

Any help would be appreciated. I did use model targets in a different project in the past using Vuforia 7.x and Unity 2018 (downgrading is not an option as I require some 2019-exclusive features) so I know how they should work and this definitely looks like some low-level issue rather than bad tracking.

Thanks!

Hello,

Typically, these are the symptoms of the 3D model's dimensions (as imported into the Model Target Generator) not matching the physical object's dimensions. I suggest that you sanity check the dimensions used in your MTG project.

R42Interactive

Mon, 08/19/2019 - 13:25

Permalink

Thanks for the prompt response, that was exactly the case - the model target generation default to a meters based scale, which resulted in a very unlikely 10 meters big model. Switched to centimeters and the tracking behaves much better.

Hi,

Vuforia needs to know the real-world size of the object it is tracking, therefore for tracking a scaled model (smaller or bigger than the actual model), a different size needs to be used for tracking a different sized object.