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GameObject Appears flipped if App started in a direction opposite to the Image Targets

January 15, 2019 - 10:48pm #1


I am trying to build an app, which upon recognition of Image Targets, instantiates a Gameobject in the Scene. Each time a new Image Marker is seen, the Gameobject spawns. This works fine in Unity Editor but after deploying in HoloLens, the Gameobject is flipped creating a mirror image of what it should have been, if I dont start the Application with the HoloLens camera facing the Image Targets/Markers. 


I had tried building a sample application before using the same settings as the Vuforia Digital Eyewear. That worked fine. Even this was fine, it would show the Gameobject appear just like it should irrespective of any direction i place the marker of start the Application, but of late, i dont understand why has this issue come up. 


Any ideas on resolving it? Any help, will be greatly appreciated. Thanks.

GameObject Appears flipped if App started in a direction opposite to the Image Targets

January 16, 2019 - 4:25pm #2


From our experience, there are several factors that can cause an augmentation to be offset, including:

  • HoloLens user calibration. MS recommends that each user perform the HoloLens calibration steps before using the device. This is obviously tedious, but when sharing HL devices within a team we've chased a similar performance 'ghosts' that were resolved when a user calibrated the device for themselves.
  • The size of your printed targets. For optical see-through devices (such as HoloLens), the printed target must match the dataset's target size exactly, as uploaded to the Target Manager. Recall that the Target Manager works exclusively in the units of meters.
  • HoloLens device calibration. All HL devices have some level of factory calibration done before shipment, and we've had to have devices re-calibrated by MS. Although this does not seem to be the source of your issue, it is something to be aware of with HL devices that the factory calibration can be compromised.

You may also want to examine the HL mesh in that area. This can be done by orienting the retical towards the area in question and "air-tapping" while in the HL shell (the home screen without the start menu - no apps running). Perhaps this will reveal some errors in the HL spacial map that are affecting their position estimations.


Vuforia Engine Support

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