Voronoi fracture divides the object into cells using random seed points. Each fragment becomes an independent rigid body.
Click on an object to shatter it at impact point Explode — central impulse on all objects
Fragments bounce off walls with the set restitution. Gravity pulls them down.
Presets
💥 Fracture — Voronoi Destruction
Click to shatter objects into Voronoi fragments! Choose materials — glass, concrete, ice, ceramic, metal and wood — each with distinct fracture patterns, sound and debris behaviour.
🔬 What It Demonstrates
Voronoi tessellation divides the surface into cells. On impact, cells separate with physics-based velocities depending on material properties.
🎮 How to Use
Click anywhere to create an impact point. Adjust cell count for fine or coarse fracture. Change material to see different breaking patterns. Gravity pulls fragments down.
💡 Did You Know?
Real materials fracture along grain boundaries and crystal planes. Voronoi-based fracture was introduced in computer graphics by Müller et al. (2001) and is now standard in VFX.
🧱 Fracture Simulation
About this simulation
This is an interactive 2D demonstration of brittle fracture using Voronoi tessellation, the same technique that powers destruction effects in films and video games. When a rigid object is struck, it splinters into independent fragments that fly apart, tumble, bounce and settle under gravity. It is interesting because it turns a single click into hundreds of physically plausible shards, mirroring how real glass, concrete and ice break apart.
How it works
Random seed points are scattered across the object, biased toward the impact location.
A Voronoi diagram partitions the shape into one cell per seed by clipping with half-planes.
Each cell becomes a separate rigid body with mass, velocity and spin.
Fragments are pushed outward from the impact, then integrated under gravity with floor and wall bounces.
Key equations
cell(i) = { p : |p - s_i| ≤ |p - s_j| for all j } — the Voronoi cell of seed s_i is every point closer to it than to any other seed s_j. Fragment launch speed follows v = F · 120 / (d + 30), where F is impact force and d is distance from the impact point.
Controls
Reset — rebuild the scene with a fresh object.
Explode — detonate every object from the centre at once.
Impact Mode — click empty space to spawn a new object, or click an object to shatter it.
Object Shape & Material — choose slab, disc, prism or wall, and glass, concrete, ice, ceramic, metal or wood.
Voronoi cells — set how many fragments the object breaks into.
Impact force / Gravity / Restitution — tune shard speed, fall rate and bounciness.
Did you know?
Voronoi diagrams are named after Georgy Voronoy but were used by John Snow in 1854 to map a cholera outbreak to a single water pump — the same geometry now shatters glass on screen.
About the Voronoi Fracture Simulation
This interactive 2D simulation demonstrates brittle fracture using Voronoi tessellation — the same geometric technique that powers destruction effects in films and video games. When you click an object, random seed points are scattered across it (biased toward the impact location), and a Voronoi diagram partitions the shape into one cell per seed by clipping it with half-planes. Each cell instantly becomes an independent rigid fragment with its own mass, velocity and spin, flying outward from the impact before tumbling, bouncing off the walls and settling under gravity. You can choose the object's shape, material, fragment count, impact force, gravity and restitution.
The simulation models six materials — glass, concrete, ice, ceramic, metal and wood — each with distinct colour, shine and bounciness, echoing how different real materials shatter. Brittle fracture is a core topic in materials science and engineering, where understanding crack initiation and propagation is essential for designing safe structures, vehicles and armour. While real materials break along grain boundaries and crystal planes rather than mathematical cells, Voronoi-based fracture captures the visually plausible result convincingly, which is why it became a standard tool in computer graphics and visual effects after being popularised in the early 2000s.
Frequently Asked Questions
What is a Voronoi diagram?
A Voronoi diagram divides space into regions around a set of seed points so that every location belongs to the region of its nearest seed. Formally, the cell of seed sᵢ is every point closer to sᵢ than to any other seed. In this simulation, each Voronoi cell becomes one fracture fragment, which is why denser seeds produce smaller shards.
What is brittle fracture?
Brittle fracture is when a material breaks suddenly with little or no plastic deformation, cracking rather than bending. Glass, ceramic and ice are classic brittle materials: stress builds until a crack forms and races through the material at high speed, splitting it into pieces — exactly the behaviour this simulation recreates.
How do the different materials behave differently?
Each material has its own colour, transparency, shine and restitution. Glass and ice fragments are translucent and bouncy; concrete and wood are opaque, dull and barely rebound; metal is reflective and springy. These differences mimic how real materials look and how energetically their fragments scatter when struck.
How are the fragments launched after impact?
Each fragment is pushed outward from the impact point with a speed that falls off with distance, following v = F · 120 / (d + 30), where F is the impact-force setting and d is the fragment's distance from the strike. Closer fragments fly faster, an upward kick is added, and each shard gets a random spin so the debris field looks natural.
What does the Voronoi cells slider control?
It sets how many seed points are scattered across the object, and therefore how many fragments it breaks into. A low count gives a few large chunks, like a coarse concrete break, while a high count produces many small shards, like finely shattered glass.
What do gravity and restitution do?
Gravity controls how strongly fragments are pulled downward as they fall, while restitution sets how bouncy they are when they hit the floor or walls — a restitution of zero means they stop dead, while a high value makes them rebound energetically. Together they shape how the debris scatters and settles.
Is Voronoi fracture how real materials actually break?
Not exactly. Real materials fracture along grain boundaries, crystal planes and pre-existing flaws, governed by stress fields and fracture toughness. Voronoi fracture is a geometric approximation that produces convincing, fast results, which is why it dominates real-time graphics rather than precise engineering analysis, where finite-element methods are used instead.
Why is fracture mechanics important in engineering?
Understanding how and when materials crack is critical to safety. Engineers use fracture mechanics to predict whether a flaw in an aircraft wing, bridge or pressure vessel will grow into a catastrophic failure, and to design materials and structures that resist cracking — a field that grew out of investigations into brittle failures such as the World War II Liberty ships.
What is the Explode button for?
While clicking shatters a single object at the point you strike, the Explode button detonates every object in the scene at once from the centre. It is the quickest way to see a whole field of objects burst into fragments, and it pairs well with the Chain reaction preset.
Who invented Voronoi diagrams?
They are named after the mathematician Georgy Voronoy, who formalised them in 1908, though the concept appeared earlier. Famously, physician John Snow used the same nearest-neighbour geometry in 1854 to trace a London cholera outbreak to a single contaminated water pump — the very geometry that now shatters glass on screen.