What it is

This was a big school assignment for the Immersive elective, and I spent a long time on it. All we really had to make was some kind of hologram, but I wanted mine to be interactive, and I think it turned out pretty well.

It's a small wooden box with a ball of particles that seems to float in the air, and you control it with your hand. Hold up an open hand and the particles are pulled towards it, so you can move them left, right, up and down. Make a fist and they get pushed away.

How it works

It uses Pepper's ghost, an old stage trick, so it isn't a real hologram. The screen lies flat in the box facing up, and a sheet of plexiglass above it, set at an angle, reflects the image towards you. The inside of the box is dark, so you only see the bright particles, and they look like they're hanging in the air. The reflection mirrors the image, so everything on the screen has to be shown the other way round. A webcam on top of the box films your hand and tracks it as 21 points.

How I made it

I started with a Raspberry Pi, put it at the bottom and placed a screen on top of it. Then I built a small case around it and set the plexiglass at an angle, so the image from the screen would reflect off it. On the Pi I run Python software that creates the particles and reacts to your hand.

The box is made of wood that I laser cut with the machine we have at school. It's this small because I didn't have much material or money, so I just used what was lying around at school.

How it went

I'm really happy with this project, and I put a lot of work into it. The outside could maybe have looked nicer, but for me it was more about getting the technical side right. You can always make the outside look better later.

I also tried a second version with a crystal, where the light goes through the stone and comes out at the top. It didn't work as well as I wanted, and a bigger stone was really expensive, so I left it at that.