Docs · Sandboxes

One mechanic, no genre

A sandbox shows a single engine primitive in isolation, knobs exposed — how a part is used, without smuggling in a whole game's design. Learn the API here; decide what to build somewhere else entirely.

Run the shelf

git clone https://github.com/hellojanpacan/hayao-js && cd hayao-js
npm install && npm run dev
# then open http://localhost:5180/sandboxes/<lab>/

Physics

physics-lab

createRigidWorld

Rigid bodies, joints, raycasts. Spawn and drop bodies; tune gravity and restitution.

Source

Particles

particle-workshop

Particles + PARTICLE_PRESETS

Every preset, with count, gravity and spread on sliders.

Source

Camera

camera-lab

Camera2D + CameraController

Deadzone, smoothing, shake and bounds — feel the follow rules directly.

Source

Pathfinding

pathfinding-demo

astarGrid / floodFill

Paint walls, move the goal, toggle diagonals; watch the search respond.

Source

Juice

juice-lab

EASINGS + AnimationPlayer + spring

Every easing curve side by side — pick feel by eye, not by name.

Source

Procgen

procgen-lab

generateCave + valueNoise + autotile

Re-roll the seed, tune fill and smoothing; same seed, same cave, every time.

Source

Synth

synth-lab

the audio bus

Pitch, wave, envelope — hear a SoundSpec take shape as you drag.

Source

Animation

anim-lab

Bone2D + ClipPlayer + Blend1D + IK

Blend idle↔wave, reach for the pointer with IK, toggle the skeleton overlay.

Source

WebGL effects

webgl-lab

WebGL2Renderer + BLOOM_PIPELINE

Cycle eight post-process effects; burst particles; stress-test the storm.

Source

Cards

card-lab

makeCard + resourceGlyph

Four card anatomies from the slot-stack kit, in day and night themes.

Source

Hero rig

hero-lab

the duotone hero + seven clips

The whole cast sheet playing at once — jump, spawn and death on auto-replay.

Source

2D lighting

light-lab

LightLayer + PointLight + occluders

Two lights carving pools out of ambient dark; drive one, the other orbits.

Source

The sandbox contract

Lighter than an example, honest like one

  • Import only from @hayao — same seam as everything else.
  • Deterministic — re-roll a seed and it re-derives identically.
  • View nodes are cosmetic — knob state is canonical, paint stays out of the hash.
  • Headlessly inspectable — every lab exposes a probe(world).
  • No win, no lose, no genre — if it starts feeling like a game, it belongs in examples/.