VR Iron Flower
My Role
Experience design, VFX development, interaction & optimization
Origin
Iron flower fireworks originated during the Northern Song Dynasty in Henan Province. Blacksmiths heat molten iron to 1600°C and strike it against willow boards, creating cascades of golden sparks. In 2008, this craft was designated a National Intangible Cultural Heritage of China.
Today, only a handful of masters remain—most over sixty. The demanding physical requirements and industrial modernization have nearly extinguished this living heritage.
I wanted to give people a way to experience this craft—not as passive observers, but as active participants.
Design Decisions
Why VR, not video?
Traditional media lets you watch; VR lets you participate—feel the heat, control the rhythm, experience the ritual. Preserving a craft, not just its knowledge.
How do you convey 1600°C heat in VR?
VR cannot transmit real temperature. I used visual cues (radiating glow, heat distortion), spatial audio (crackling flames, sizzling metal), and controller haptics to create a multisensory illusion of intense heat.
How do you balance authenticity with accessibility?
Real iron flower performance requires years of training. I simplified the mechanics to three core actions—scooping molten iron, striking it skyward, timing the release—while preserving the essential rhythm and physical gestures of the craft.
Experience Flow
Melt
Heat iron ore in the furnace to 1600°C. Watch the progress bar and listen for the metal's changing sounds as it approaches the ideal temperature.
Strike
Scoop molten iron with a long-handled ladle and strike it against the wooden board. Timing and angle determine the spark pattern.
Lotus Lantern
Touch the lotus lantern to ignite it. Push it gently onto the river and watch it drift across the water, its glow reflected in the ripples.
Sky Lantern
Touch the sky lantern to light its flame. Release it and watch it rise into the night, joining dozens of lanterns drifting across the starlit sky.
Full Walkthrough: from furnace to fireworks to lantern release.
Technical Implementation
Particle Dynamics
Built with Unity VFX Graph. Each spark follows physically-based trajectories with temperature-driven color gradients—from white-hot cores to deep orange trails. Optimized particle count from 10k to 2k while maintaining visual density.
Water & Light
Real-time water surface rendering with reflection probes. Lanterns use soft-body physics for natural floating motion. Volumetric lighting creates the atmospheric glow.
Scene & Interaction Design
Designed navigation zones using collider boundaries and visual cues. The experience flows through three interconnected areas—furnace station, striking platform, and river bank—with smooth teleportation and guided progression.
Haptic Design
Custom vibration patterns simulate material feedback: the weight of the ladle, the impact of striking, the resistance of molten metal. Thermal intensity mapped to controller intensity.
Reflection
Digitizing cultural heritage isn't about pixel-perfect replication—it's about distilling essence. What makes iron flower meaningful? The rhythm, the heat, the ritual.
Early builds ran at 45fps on Quest 3. After profiling, I rewrote the particle LOD logic and cut count from 10k to 2k—stable 72fps without losing visual impact. Cut scope from 6 to 4 interactions after playtests revealed cognitive overload.
Next: fieldwork with actual craftsmen, and exploring multiplayer co-op to capture the communal spirit of the tradition.