Stockholm Light

Digital Fireworks

Client: Atracta
Project: Digital service

Atracta is a company that operates advertising screens (and we’re talking SCREENS) in some of Stockholm’s most well-trafficked squares and avenues. To celebrate New Years Eve 2020, they wanted to do something special.

What could really dazzle the citizens of Sweden’s royal capital? You know, ignite the night… and let it shine…

Lighting up Stockholm

Given the nerds we are for interactive digital experiences, we thought it would be fun to let people play a role in making the fireworks happen.

After brainstorming with Atracta about technological possibilities, we honed in on the following idea: to create an app that would let users shoot up digital fireworks onto the big screens with personalized greetings.

And we would use the exposure to do some good too, by giving users the opportunity to donate to a charity. A donation would get you a really big firework.

Oooh… ahhh….

Users could choose which of Atractas four screens they wanted their firework to play on: The Big Bang at Stureplan, The Façade on Kungsgatan, Twin Screens on the way to Arlanda, or the Elevator towering above Katarinahissen.

They could also choose the type of firework, the color, and fill in their greeting. That “order” was processed through a custom-built API and sent to the individual websites we built for each screen.

We integrated this infrastructure with Atracta’s own program so the fireworks would show up between their commercial loops.

How to code a firework

Everything about each firework needed to be dynamic: the size, color, duration, timing. There was no other choice but to actually make them from code. We decided to go with particles.

A single particle is a tiny bitmap image whose movements are controlled by Javascript. A spark, if you will, that could be combined with thousands of other sparks to create the actual firework. We hosted it all on a game engine called Defold, which is — fun fact — a completely open source engine created by some lovely people in Malmö.

It took a special blend of art + math to make the fireworks mimic reality. This involved programming sine and cosine waves to create the arcs and smoke trails, adding gravity, simulating wind, and so on.

  • Download app & choose screen
  • Choose firework style & color
  • Dedicate it to a loved one
  • Give to a charity from the list

End scene

When the clock struck twelve… boom, bang, pow, whizz! Our digital fireworks were playing perfectly all across the city.

Looking up from Stureplan that night, the folks at Atracta were really happy with the result. And we were too. We loved the opportunity to spread some interactive cheer using the art of web-based motion.

And the fact that our creation didn’t leave our dog friends trembling in a corner, that’s satisfying too.

Selected work