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Switch between Image Target and Ground Plane

December 9, 2019 - 1:49am #1

I have a 3D model and I'd like to have to option to attach it to an Image Target OR a Ground Plane. The way I implemented this is by keeping the model as a child of the Image Target, and pressing a button it's parented to the Ground Plane Stage. Pressing the button again brings the model back into the image Target.

It works, but the model is VERY unstable and jittery, sometimes while being parented to the Image Target it behaves like it's in a mid air stage (stays in the same real-world point). I have tried different approaches, even having a copy of the 3D model in both trackables, unregistering targets, nothing seems to work. Am I missing something?

I saw there is a lengthy discussion about a similar problem and it looks like Image Target and Ground Plane don't work well together out-of-the-box, while I had no problems making them work independently (i.e. a scene with only Image Targets or only one Ground Plane)

 

I'm using Unity 2019.2.5f1 and 2019.2.9f1, this happens in-editor on Windows 7 and the last Mac OS using the webcam and on an iPad Air 2 (no ARKit), haven't tested on other devices.

Switch between Image Target and Ground Plane

December 12, 2019 - 6:11am #4

Hi,

I determined the behavior to be related to the Extended Tracking.

Scenario1: ImageTargets and GroundPlane in different scenes

Extended tracking is only activated on the GroundPlance scene. Hence you do not see the mentioned the behavior in the Image Target scene.

Scenario2: ImageTargets and GroundPlane in  the same scenes

Extended tracking is activated as soon as you start the scene and you see the jittery behavior

 

I've also brought the behavior internally to the Dev team and they mentioned that in the Extended Tracked scene you get to see the last pose of augmentation, in comparison to the Image Target scene where when the tracking is lost, the augmentation disappears.

To address this issue I found two workarounds:

1. Split the scene in two, you already tested this and it works as expected

2. In 8.6.7 we now have the possibility to render content based on the Trackable result. This means that the Image Target can be confirmed to render the augmentation based on the status Tracked and not on Extended_Tracked. Ignoring the Extended Tracking which in this case should resolve the behavior faced. More info, here: https://library.vuforia.com/content/vuforia-library/en/articles/Solution/How-To-Use-the-Trackable-Base-Class.html

and Release notes: https://library.vuforia.com/articles/Release_Notes/Vuforia-SDK-Release-Notes

Thank you.

Vuforia Engine Support

 

Switch between Image Target and Ground Plane

December 12, 2019 - 1:13am #3

Hi mcotora and thanks for the reply,

I have reproduced the same issue on an iPad Pro 12,9" (3rd gen). I took two videos with this device.

The problem I mentioned in my first post: https://youtu.be/bQABFKRz5JI

The same app but with Image Target and Ground Plane split in two different scenes: https://youtu.be/n9w-P4z_c2g

I'm also sending you a private message with a barebone Unity project which you can use to reproduce the issue.

Switch between Image Target and Ground Plane

December 10, 2019 - 2:13am #2

Hi,

I believe the behavior is affected by the devices you use to test your scene. My concern is that both devices although can run GroundPlane are limited in the available resources. For ex. webcam doesn't have any sensors and it relies on Emulator Ground Plane.pdf to work.  Ipad Air 2 is a device which was not designed with AR in mind.

Could you please share a video of the jitter? Also would it be possible to share the project to test the behavior?

Thank you.

Vuforia Engine Support

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