2024 · Designer & Developer

GestureSketch

A webcam-driven mid-air drawing tool for expressive therapy

The Problem

Conventional drawing apps require styluses, menus, and technical confidence. For therapy clients seeking expressive creative outlets, this friction kills the flow before it starts. GestureSketch strips the interface down to a single camera and a set of natural hand gestures.

Role

Full-stack designer and developer — research, interaction design, prototyping, and implementation.

Timeline

6 weeks

Tools & Methods

  • MediaPipe (hand landmark detection)
  • p5.js (real-time stroke rendering)
  • Figma
  • SVG export

Interaction Model

I designed a three-gesture vocabulary that maps to natural hand movements: index finger + thumb pinch to draw, thumb + ring finger to cycle colors, thumb + pinky to undo. Button backups for undo and clear sit at screen edges as a confidence-building safety net for new users.

Key Design Decisions

  • Dead-zones around each gesture trigger to absorb jitter from natural hand movement

  • Immutable strokes — each stroke stores its own size and color, preventing accidental overrides

  • Minimal UI — no toolbars, no menus, nothing that interrupts creative flow

  • SVG export for persistent, shareable creations

  • LLM prompts deferred to v2 after tuning issues — shipped a clean, fast core first

Therapist Validation

An art therapist reviewed the prototype and praised its ability to bridge the digital/human connection in online therapy sessions. The naturalness of mid-air gestures made the tool feel less like software and more like an expressive medium.

Technical Architecture

  • MediaPipe hand-landmark model running in-browser at 60fps

  • p5.js canvas for real-time stroke rendering

  • Gesture buffer system with configurable dead-zones to prevent false triggers

  • Per-stroke metadata storage (color, size, timestamp)

Outcomes

3Gestures in vocabulary
60Frames per second
Therapy validation
4v2 roadmap items