-Trying Google Cardboard- hardware and impressions

Hello, this time I made a DIY Google cardboard, did a mod , and did a performance benchmark of it.


I used the blueprint of original cardboard from google.
-Original Material list
 25mm 3x zoom loupe(which have 2 lens) \100
 3x zoom loupe with possession x 2(didn't use) \200
 swimming goggle \100
 plastic tape \100
 magic tape \100
 magnet      \100
 cardboard   \0
 rubberband \0

-tools
 AlonAlpha(the world strongest glue from japan which glued against the repulsion of Neodymium Magnet, pretty affordable price, at least in Japan)
 Cutter
 Sissors

The overall material cost was \700.(about $7)
My original mod was using the swimming goggle head rubber to make the google cardboard able  being mounted to head without holding it.

Impression/Comparison about Google cardboard

1. I have to calibrate the position of the smartphone everytime when I attach the smartphone to the Google cardboard. It quite bothers me doing the calibration every time setup. DK2 is extremely easy to calibrate.

2. You can't feel direction of the sound and get less enjoying Virtual Reality experience if you are not using headphone or external speaker when enjoying VR contents. Using headphone in Google cardboard will boost the enthusiasm of the VR contents. Oculus DK2 doesn't have speaker.

3. Vibration is a awesome feature for VR in google cardboard. Your head can feel shock of the google cardboard vibration caused from the smartphone. Oculus Rift DK2/DK1 doesn't have vibration. I tried Gear VR vibration(smartphone based head mount virtual reality device), but the vibration was small.

4. The FOV is a little small compared to Oculus Rift DK2, but the resolution of the monitor is pretty good. Also able to feel 3D vision. Looks like the small FOV problem can be solve choosing better lens.

5. Google Cardboard just uses odometry to locate the head position. This will cause position drift. Position Drift is not good for the VR experience. I think it'll be better if we put some AR tag and track the position of the cardboard by tracking camera. <a href="http://gogglepaper.com/">Looks like someone have been done this before.</a>

6. I don't like google cardboard button controller. I think it's better to use external controller.

7. Current version of Cardboard can't change the zoom rate of lens. This is not good because people eye sight vary. Need a variable zoom rate feature like Gear VR for common use.

8. This cardboard blueprint is opensource and just requires inexpensive parts to create this. Very good resource to study/start prototyping VR/Head Mount Displays, even for children, I think. Next time I'm going to make my original blueprint of the smartphone type headmount display.

9. The goggle rubber band mod was completely success. In the normal Google Cardboard, you have to hold it by your both hands, and this feels you're just looking some 3D movie with less interaction. Mounting to your head will make your VR experience better by enabling the functionality to do interactions with controllers/hands. Next time I'm going to use more robust parts for head rubber.