When using MR with "Phone+Viewer" setting, Image Target and Ground Plane together, stereoscopy function usually goes wrong.
Normally, when it's under stereoscopy, the virtual object you get close to should get close to the nose as your view point.
That means, the virtual object you get close to should get close to right side in your left-eye view and get close to left side in your right-eye view.
(Example Video Link: https://youtu.be/orK1v4agNjs)
But in this video (Link: https://youtu.be/0wlNSIDnoPI?t=20) start with 20 seconds,
You can find the object I get close to actually move opposite way.
Hence, when wearing HMD, the stereoscopy goes wrong. User can not see the object clearly since the conception of the position is totally different in left-eye and right-eye.
I first encounter since June 2018. But I used to think it happened because I changed the parameter of some camera setting and led to it until recently I started new empty project.
Steps to reproduce
1.Enable Vuforia in Player Settings> XR Settings. Check Vuforia AR supported and VR supported with Vuforia SDK.
2.Change Vuforia configuration from "handheld" to "Phone + Viewer".
3.Replace Main Camera with AR Camera
4A. Add Ground Plane object and Plane Finder object. Place some mesh object under Ground Plane object
4B. In Vuforia configuration, Check Device Tracker with default settings (Tracking mode: POSITIONAL / Fusion mode: ...Model and Ground Plane)
5.Add Image Target object. Place some mesh object under it.
6.Build for iOS
7.Export to iPhone by XCode
8.Execute app. Trigger Image Target. (It only happened after app detect Image Target and only happened when using MR, Image Target and Ground Plane together)
//Already tried both World Center Mode Device/First Target), it doesn't matter.