Project a simple hologram over your smartphone

TLDR : DIY proof-of-concept holographic dice with a dice app and a glass tile. Drill a hole underneath a Mirascope to position the tile within the belly of a very cool hologram device. Total cost of materials is under $20 (not counting the smartphone).

Consider the Mirascope

A mirascope tricks the eye into seeing an object where it shouldn’t be. Its construction is simple. It is an oblong container that looks like a flying saucer. Its interior features a shiny mirror surface so that, if you drop an object inside, say a small coin, it “re-appears”, floating above the mirascope.

The illusion is arresting. It looks real even when you move your head a little because the mirrors show you all sides of the coin.

Now, what if we could replace the coin with an object that we can control?

Going digital

Researchers at ETRI did this at great expense. They made a 3" animated Rubix Cube. They wield the power to project it and any small 3D object inside their mirascope with an array of lasers. That’s pretty fancy.

And hard.

How do you project an arbitrary 3D object? Not easily, and other research prototypes are similarly cool, but nascent, complex and expensive.

I wanted to see if the Mirascope solution could be done on a home budget. Because a limited little holographic prototype would be cheap, but ready — right here, at the table. We could play with it now and see how it survives in everyday life.

“Give me a chance!”— your DIY home Mirascope ideas

So instead of an arbitrary 3D shape, let’s just go for a simple square tile. We can project a small image onto the top of small glass tile and then use that as the hologram.

But, what can you do with a holographic tile?

Dice for Hologram

We could make dice! Easy to understand and — importantly — fitting for a hologram.

Dice and holograms share a common trait. They demand attention.

Holograms are a spectacle, drawing your focus to their content (a princess, a galactic treasure map, or schematics of a space moon) — they invite you to really look.

The same is true of dice. A die roll in a game draws the eye of every player. Its outcome is a turning point in the narrative of the game.

So, when it’s time to roll the dice, let’s roll a hologram.

How To

Supplies

A smartphone

2 Toy mirascopes (6" model)

Black foamboard

1" (or smaller) wide glass tile

Tape, Compass, Cutting tools, etc…

Why 1"? The mirascopes that I bought look best with a small coin the diameter and height of an American quarter. A 1" tile is just about the same in width. Any larger and the illusion will be flawed. A little smaller might be a possibility, since it will be more forgiving of the angle at which the viewer looks into the mirascope.

Why 2 Mirascopes? You are welcome to buy one mirascope if you have the tools to drill a hole in the bottom of your mirascope. Buying two was my quickest solution for putting the smartphone and tile inside the lower half of the mirascope. The trade-off is that the hole is a bit larger than I would have liked, which can interfere with the illusion.

Step One: Produce a 1" image

For this, I programmed a dice app (in React Native, Github). It has a dice face. When you place your finger on the screen, the dots scramble around as if to mean it is rolling. When you lift your finger, a random dice face appears.

roll: Math.floor(5 * Math.random()) + 1

You get the idea.

Here’s how to install it on your phone: Install Exponent (iTunes, Google Play), start Exponent and load this experience URL:

exp.host/@giffordcheung/holodice

Step Two: Give it some texture

Place a glass tile atop the image. This is the cheapest way give a sense of dimension to your flat image. There is a lot of room for innovation here, so we can come back to this later.

You can buy 1" glass tiles from Amazon or your local craft store, search for either “glass tile” or “cabochon”. If you have a plastics shop (e.g. Seattle’s TAP Plastics), they also sell small plastic tiles.

I secured my tile in place with some black foamboard and tape. This also allowed me to control the effective height of the tile inside the mirascope, keeping it about the same height as a coin. If it was too tall, then the working viewing angle is much smaller.

Step Three: Cut a hole in your mirascope

If you are handy, you can make a hole in the bottom of your mirascope with a drill or saw. My quick solution was to buy a 2nd mirascope and place the two halves together. I had to shear off the outer lip of one of the tops and then add a foam board ring as a spacer to align the reflection properly.

Go play!

Once finished, you will see the glass tile atop the mirascope. You may want to secure everything so that it won’t fall out of place during a play session. Otherwise, enjoy!