Unity version: Unity 2019.2.2f1
Vuforia version: Vuforia 8.3.8
Test Device: Google Pixel 2 XL
I've set up a simple scene in Unity to test out the ground plane detection on my device. In the editor I got it to work by printing out the ground plane image and positioning it on the ground, Vuforia had no problem detecting that image and emulating the ground plane based on that. However when making a build to my device, it does detect the ground plane, but then if I aim the camera at another flat surface, let's say a table, then tracking is completely lost and it can't detect any other surface, but then pointing back at the ground would work again. So it only works on the first surface it detects, and then it just looks for that surface only. If I pointed it at the table first, then I wouldn't be able to detect the ground because it would remember the table as the ground. I'm not sure if this is the intended way for this to work or if I am implementing something wrong.
Sometimes I would launch my test app and right on launch, it would quickly detect a surface (the wrong surface) based on a zoomed in view of the table, but then if I move the camera around and try to aim at the ground to get that detected, it wouldn't detect it at all, it's as though it thought the first (false) planar detection is the right detection and then it would only look for that, and even pointing at the table again wouldn't work, I would completely lose tracking...
I played around a bit with the ARCore requirement setting, it had no apparent effect on this.
I am also facing another weird issue, when I can actually detect the ground plane and then place an object on it, sometimes the plane detection flickers and starts jumping back and forth between 2 positions, making the placed object start jumping around as well and growing/shrinking in size randomly. This is an AR-breaking issue for me and my project, I hope someone here can help.
View video demo here: https://streamable.com/7tm0s
This is a video that shows everything I explained here, I've pretty much followed Vuforia ground plane detection tutorial, nothing more. At the end of the video you can see how the placed object suddenly gets much bigger, due to the plane detection flickering and either moving the anchor much closer to the camera, or moving the camera much closer to the anchor, not really sure what's happening here but I know for a fact that the objects scale is not changing, it is simply its distance from the AR camera that is changing.
Looking forward to hear your answers, thanks!