The idea for the Cardboard Hololens is simple. Its design inspiration comes from google cardboard VR. Just like cardboard it uses your phone to display steroscopic images to simulate 3D content. But instead the phone is placed above your eyes and then the images are then reflected via semi reflective/ transparent glass into your field of view. This way the 3d content is mixed with the real world at a fixed depth.
Now the actual display technology behind the Hololens is far more advanced but, this is a work in progress, first build prototype. I will continue to work on new, and improved versions, and post DIYs so you can follow my progress. The ultimate goal for the cardboard hololens is to be a simple & cheap solution to simulating AR without having to pay for an expensive Dev Kit.
Step 1: Constructing Prototype #1 (materials Needed)
1. The items I used:
- A cardboard Amazon shipment box - to build the frame
- Lens from a color cross VR headset - to focus the stero images onto the glass
- Polycarbonate glass - used to reflect the images into field of vision
- Black electric tape and velcro tape - to hold the frame together, and provide a smooth finish
- iPhone 6 plus - the image source to provide the 3d content
- Plastic Cutter - to cut the polycarbonate glass
Step 2: Measure & Cut
Next use an exacto knife or box cutter to precisely cut up the cardboard into 5 pieces. Essentially you are going to be building a rectangular box. The length and width of the pieces should be based around the screen size of YOUR phone. The height of pieces depends on the focal length of the lens. For the iPhone 6 plus I found these measurements to be most effective.
- Cut 2 holes in the base piece of your cardboard cut. The distance between the two holes should be 1inch.
- I also cut out a long piece of cardboard and bent it in 2 places. This is optional but it can be used as a fastener to hold your phone in place so you won't have to hold it with your hands. You will need 2 pieces of velcro to accomplish this: one on the fastener and one on the box frame
- Next wrap all your pieces in electric tape to get a smooth finish. The black color of the tape will help keep in the light. I also used the tape to attache the fastener to the side of the carboard piece
Step 3: Assembly of Frame
Carefully tape the pieces together to form a rectangular box. As you can see it resembles google cardboard
- Insert the lens into the box as shown above.
- The fastener should function to wraparound the top opening of the box so it will secure the phone. I used a hot glue gun to glue on the velcro strips as shown above
Step 4: Glass Assembly
Next your are going to cut out your reflective material into pieces as shown in the top left photo
- Assemble the pieces using clear scotch tape to form a visor like design as shown in the pictures
- Use electric tape to tape the visor to the cardboard frame as shown to ensure a rigid structure
- The long piece of reflective glass should be angled at 45 degrees in-front of your eyes so that the glass touches your nose
Step 5: Comfort (Optional)
As you can see I super glued a soft foam to the box. This is an optional step, but it adds a comfort factor as the box will be placed against your forehead
Step 6: Image Setup
Now run the 3D test scene. Rotate your phone landscape. Turn your screen brightness all the way up. Open the fastener and lay your screen horizontal aligned with the lens. The box is meant to be held with the box above your eyebrows and the glass in front of you eyes. Look through the glass reflector. Once you see the solar system in your field of vision it might need to be adjusted if it appears double imaged. Once correctly aligned the solar system will appear to have 3d stero depth. Once correct close and velcro the fastener
Step 7: The View
This is what the solar system should look like when viewed through the glass. The picture above shows the image being projected through one lens but when view through both it should give a 3d impression at fixed focus depth