# Following the Blue Trail: an interactive space for children to meet their city’s wildlife

- **Client:** Academic project — proposal for Parque de la Conservación, Medellín
- **Year:** 2025
- **Role:** Team lead, working prototype (ESP32 and gesture-controlled game), space render and definition of the experience
- **Tools:** ESP32, OpenCV, Streamlit, Python, Blender

A proposal for an interactive installation about the wildlife of the Aburrá Valley for children, validated with a working prototype of physical buttons (ESP32) and a gesture-controlled game using computer vision.

## The context

How do you get a child from Medellín interested in the bat, the
motmot, the opossum or the glass frog, the animals they share a city with
without knowing it? That was the challenge of this academic project done by
a team of 3: designing "Following the Blue Trail", a temporary interactive
installation proposed for Parque de la Conservación, aimed at children aged
8 to 11 and connected to the concept of Effective Public Space. I led the
team and took on the complete working prototype, the render of the space
and much of the definition of the experience.

The full proposal defines a space of 8.5 × 9.75 meters where blue tracks on
the floor guide the child to a monitor with physical buttons for choosing an
animal; the choice transforms the entire atmosphere (light and sound) and
activates minigames on touchscreens that let the child live what that animal
experiences in the city. The journey is designed as an emotional arc in five
stages: from the curiosity of the entrance to the inspiration of the exit.

## The key design decision

An installation like this costs tens of millions of pesos. Before proposing
that investment, we had to answer the uncomfortable question: do the
interactions work? We structured the spatial proposal in a comprehensive design
poster defining the dimensions, atmosphere and architecture of the module.

[Image: Design poster on crumpled cream paper texture: floor plan and side-view diagrams of the 8.5 by 9.75 meter pavilion, illustrations of bat, opossum, motmot and glass frog, and experience icons.]
[Full-size image: https://juancamilo492.online/evidencia/siguiendo-la-huella-azul/one-page-design.png]
Overview of the spatial and architectural design of the “Following the Blue Trail” installation, showing pavilion sections, screen layouts and core project pillars.

[Image: Four-quadrant diagram on cream paper showing the pavilion floor plan with different lighting moods: green for the motmot, blue for the bat, dark green for the opossum and light green for the glass frog.]
[Full-size image: https://juancamilo492.online/evidencia/siguiendo-la-huella-azul/variaciones-espacio.png]
Lighting variations of the space based on the selected animal: each choice alters the room’s ambient lights and overall atmosphere.

The decision was to **validate cheaply what would be expensive to build**: a
working prototype with an ESP32 simulating the physical button panel and a
minigame controlled by hand gestures, using computer vision with OpenCV on top
of Streamlit. With that we could put real people in front of the space's two
central interactions without building the space.

## The validation

To map the user experience step by step, we designed a five-stage customer
journey map spanning from initial contact in the public space to exiting the
pavilion.

[Image: Horizontal Customer Journey Map matrix split into five colored columns for each stage: Discovery in green, Curiosity in blue, Fun in orange, Creation in purple and Exit in red.]
[Full-size image: https://juancamilo492.online/evidencia/siguiendo-la-huella-azul/journey-map.png]
Customer Journey Map detailing moments, touchpoints, value points and the emotional curve of a child throughout the walkthrough.

We ran tree testing across two sessions with 10 participants at EAFIT's
Medialab, with a structured script, informed consent and video recording. A
limitation we reported transparently: because of scheduling logistics, the
participants were university students and not children. That was enough to
evaluate the information architecture, but not enough to consider the
children's experience validated.

[Image: Nine-photo collage matrix documenting prototype testing at EAFIT's Medialab: participants testing gestures in front of the computer and gathered around a work table with faces protected for privacy.]
[Full-size image: https://juancamilo492.online/evidencia/siguiendo-la-huella-azul/pruebas.png]
Photographic record of validation sessions at EAFIT's Medialab: gesture minigame evaluation and feedback discussions with participants.

The results gave a revealing contrast:

- **Physical buttons: 80% success.** Navigating the animals' information
  flowed, with minor adjustments (icons on the buttons, relocating the back
  button).
- **Gestures: 50% success.** Half the participants couldn't control the
  game. The gestures weren't intuitive and permanent visual cues were
  missing: two issues of serious severity that we documented along with
  their recommended redesigns.

## The outcome

The project closed with a proposal ready to be implemented: an executive
summary, an assembly sheet with plans, an equipment list, a two-week
schedule and an estimated budget.

[Image: Technical floor plan with measurements and equipment breakdown for the interactive pavilion: includes component legend with multitouch kiosks, LED spotlights, speakers, VR headsets and Arduino, dimensioned 8.5 by 9.75 meter top view, and four side elevation views.]
[Full-size image: https://juancamilo492.online/evidencia/siguiendo-la-huella-azul/planos-medidas.png]
Technical assembly sheet featuring dimensioned pavilion blueprints and required equipment breakdown (multitouch screens, LED strips, speakers and VR headsets).

Additionally, we modeled the spatial experience in an animated 3D render to
visualize how lighting and screen content respond to a child's interactions.

[Video: 3D Render of the 'Following the Blue Trail' interactive space — https://www.youtube.com/watch?v=GjFoIYIuFTI]
3D walkthrough of the interactive pavilion illustrating the immersive atmosphere, shadow play and lighting response based on the chosen animal.

And with a prototype that had already shown what worked and what didn't. The
most "innovative" interaction (the gestures) turned out to be the most fragile,
and the simplest one (physical buttons) the most solid: exactly the kind of
finding that justifies prototyping before building.

## What I learned

This project left me with a bittersweet lesson: we never managed to test
with children, our real users. Validating with university students gave us
valuable findings about the architecture and the interactions, but the most
important question, whether a 10-year-old enjoys this, stayed open. I learned
that access to the right users is arranged from day one of the project, with
the same priority as the prototype; if you leave it for the end, you end up
validating with whoever you can and not with whoever you should.

And the data confirmed something I now apply to everything I design: the
simplest interaction beat the most novel one hands down. Innovation isn't in
the sophisticated gesture, it's in it working.

Source: https://juancamilo492.online/en/projects/siguiendo-la-huella-azul/