examples · a quadtree library for 2D collision detection
Move the cursor to query a static scene. Hit shapes light up, and yellow arrows show the MTV response vector for each collision. Toggle the tree overlay to see spatial partitioning live.
Survive escalating waves of 500+ enemies. MTV resolves crowd separation every frame — enemies jostle and press rather than stack. Blast nearby enemies away using MTV-driven knockback. How long can you hold out?
Spawn glowing blobs that collide and bounce off each other. Adjust gravity and drag in real time. Right-click to attract everything to the cursor.
150 flocking agents. Each boid queries its spatial neighborhood every frame for separation, alignment, and cohesion. Toggle the tree overlay to see the partitioning in action.
A scrolling platformer rendered with Pixi.js (WebGL/WebGPU). A rolling circle player traverses a wide level — simplequad handles circle-vs-AABB MTV collision; Pixi.js handles the rest.
Classic side-scroller. Player jumps between platforms collecting coins. Collision resolution via MTV keeps the player standing on surfaces.
Classic brick-breaker. The ball is a circle; bricks and paddle are AABBs. MTV from each query hit drives both the push-out and the reflection angle — no manual geometry needed.
Shoot enemies that swarm from the edges. Escalating waves and enemy HP stress the tree's circle queries across many dynamic objects.
Prey flock and flee using spatial neighborhood queries. Predators hunt via a wide search circle and eat on collision. The same tree drives both behaviors every frame.
Classic Asteroids with a twist. Large rocks split into smaller fragments on impact. The tree handles mixed-size circle queries each frame as the field grows.
Place fixed towers to shoot enemies following a winding path. Each tower queries a range circle every frame — demonstrating stationary queriers against many path-following objects.
Upload any image to watch a quadtree progressively compress it — subdividing only where pixel colours vary, collapsing uniform regions into a single averaged colour. A different side of spatial data structures.