6 days ago

Immersive Bar

Pour Sense HAT ‘ingredients’ to mix virtual cocktails in this fascinating blend of the physical and digital worlds.

Mixed reality (MR) is the merging of the real and virtual worlds to produce new environments where physical and digital objects co-exist and interact in real-time. And what better way to illustrate the concept than by mixing virtual cocktails with ingredients represented by Raspberry Pi boards equipped with Sense HATs?

This article first appeared in The MagPi 85 and was written by Phil King

This was the idea of three students at Copenhagen Institute of Interaction Design (CIID) when tasked, during an ‘Immersive Experiences’ course, with creating a joyful mixed reality experience which offers a recurring element of surprise.

“Emerging technologies such as mixed reality are increasingly finding their way into everyday life,” explains Aditi Vijay. During a brainstorming session, she and fellow students Laurin Kraan and Minatsu Homma came up with the concept for the Immersive Bar.

In this interactive game, the player chooses from three ingredients, represented by SenseHAT-equipped Raspberry Pi boards, and pours them into a cocktail shaker. “The ingredients are unknown, but by trial and error it is possible to find out what they are,” says Laurin. “In addition, the colours of the Sense HATs give a further indication of what the ingredients are.”

The player picks up a Raspberry Pi with Sense HAT and ‘pours’ its ingredient into the shaker

Pour me a drink

When an ingredient is being poured, the Sense HAT’s accelerometer detects the angle, while its LED matrix display enhances the visual effect with moving particles. An LED strip – controlled by a fourth Raspberry Pi – in the shaker visualises the liquid level. Once the shaker is full, a laptop computer – running Unity – mixes the cocktail and ‘drinks’ it before giving a rating. The whole setup is recorded by a camera and displayed on a screen.

“In total, seven different drinks can be mixed,” reveals Laurin, “from pure vodka to exotic cocktails such as the Astronaut.” The rating is based on two factors – 1. The combination of the ingredients: while some of them complement each other very well, others lead to a nauseous creation. 2. The balance of the ingredients: is the ratio between alcoholic and non-alcoholic ingredients well balanced?”

The project took the trio just five days to create. “The most difficult part was to turn our concept into a prototype within such a short time,” recalls Minatsu. “We iterated fast and explored different digital and physical feedback to create a smooth and all-round experience. For example, we initially wanted to use a water pump to raise the liquid level inside the shaker while virtually pouring the ingredients. It turned out that the pumps we had were not strong enough and we had to switch to an LED strip for the liquid level indication.”

The cocktail is rated by the computer and a score awarded, which is shown on the screen

Student demonstration

When demonstrated to other students, faculty, and guests at CIID, the Immersive Bar project was very well received and soon had people queueing up to play. You can watch a video of the cocktail-mixing fun below.

“The merging boundaries between the physical and digital worlds left the audience amazed,” says Laurin. “The demonstration soon turned into a competitive experience, in which the players tried to figure out how to achieve a better score than their friends.”