I'm developing a VR app in Unity for the Samsung Gear VR and I'm trying to implement a pointer so the user can interact with the objects in the scene. When you look at distant objects it looks fine, but when you focus on close objects (which is highly needed for the app mechanics) the pointer appears to be duplicated, so you need to center the desired object in the middle of the points :P
What I've tried
-Using the GvrReticlePointer that comes with the GoogleVR package for cardboard
-Creating my own pointer by adding a canvas to the main camera with an image in the center
-Changing some of the Camera settings like field of view, stereo separation, etc.
-Configure my phone via a QR code https://i.sstatic.net/M0JXn.jpg
Steps to reproduce (With canvas added to camera)
1.- Create a simple scene with a few objects to look at in Unity
2.- Set build settings for android
3.- Configure player settings to enable "Virtiual Reality Supported"
4.- Add Oculus as Virtual Reality SDK
5.- Set package name and minimum API level
6.- Add a canvas to the camera
7.- Add an image to the canvas, a cross will do the job
Observations I'm using Unity 5.6.0b10 since google cardboard's site recommends using this version for the GoogleVR package. And I'm using the Samsung Gear VR with a Samsung Galaxy S6 edge + phone.
Solved
Apparently this is a well documented issue called voluntary Diplopia, and it's a human bug not a software one (read here, Unity's documentation, section The Reticle Interaction in VR).
The problem is trying to put the reticle at a fixed point in the user interface, like traditional 3D games. When looking at closer objects in VR this is going to cause this seeing double problem.
The solution is to position the reticle at the point in the 3D space the user is looking at. If he's looking closer, the reticle is drawn closer. Of course now you also have to scale the reticle accordingly, so the users can see it the same size no matter where they're looking at.
Unity also provides some example scripts about this, you can find them in the assets store, is called VR Samples.
Now I have performance issues (I'm working on mobile platforms): sometimes, when you turn your head fast you can see the reticle where it was drawn before. But looks way better than the double reticle version.
