@adatechnology/game-fluids-three

three.js renderer for @adatechnology/game-fluids. It only reads the simulation state, so it draws exactly what the deterministic world says (a LAN client with the same state draws the same liquids). three is a peer dependency used for types only: you pass your own THREE instance at runtime.

What it draws:

• Liquid in containers: inside every bound object, the container's inner shape clipped by the world-space liquid surface, so the top is always on the surface plane whatever the tilt (upright, lying down, upside down). One material per liquid (colour, opacity, roughness from gloss). Steam puffs rise from a hot surface.
• Streams: a thread along the ballistic path (tube updated in place) that narrows as it accelerates, with a drop that grows at the leading tip and a trailing drop when it ends; thin streams are a sequence of falling drops.
• Stains: a smooth fan from the 16 flow-front radii (never a perfect disc), lying on the surface plane a hair above it (polygonOffset, oriented by the stain's normal), tinted by the liquid with a soft rim, plus an inner glossy fan at wetRadius that reflects the environment and recedes while it dries. A dried mark is a faint matte patch.
• Splashes: pooled round droplets (THREE.Points with a small ShaderMaterial, the round sprite is drawn in the fragment shader, no textures).

Lit with the standard material, no transmission, a handful of draw calls, fixed budgets per quality.

Install

pnpm add @adatechnology/game-fluids-three @adatechnology/game-fluids three

Browser without a bundler (the global is GameFluidsThree; it bundles the few game-fluids helpers it calls, you still load GameFluids to create the world):

<script src="https://unpkg.com/three/build/three.min.js"></script>
<script src="https://unpkg.com/@adatechnology/game-fluids/dist/index.global.js"></script>
<script src="https://unpkg.com/@adatechnology/game-fluids-three/dist/index.global.js"></script>
<script>
  const fluids = GameFluids.createFluids({ seed: 1 })
  const view = GameFluidsThree.createFluidRenderer(THREE, { scene, fluids })
</script>

Usage

import * as THREE from 'three'
import { createFluids } from '@adatechnology/game-fluids'
import { createFluidRenderer } from '@adatechnology/game-fluids-three'

const fluids = createFluids({ seed: 7 })
fluids.addSurface({ id: 'floor', point: [0, 0, 0], normal: [0, 1, 0], halfSize: [10, 10], porosity: 0.05 })
fluids.addContainer(
  { capacity: 0.25, liquid: 'coffee', liters: 0.25, temperature: 90, shape: { kind: 'cylinder', radius: 0.04, height: 0.1 }, opening: 0.04 },
  { id: 'cup' },
)

const view = createFluidRenderer(THREE, { scene, fluids, quality: 'medium', envMap })
view.bindContainer('cup', cupObject, { innerOffset: [0, 0.005, 0] }) // inner bottom centre in the object's space

// every frame
const p = cupObject.localToWorld(new THREE.Vector3(0, 0.005, 0)) // world position of the inner bottom centre
fluids.setTransform('cup', [p.x, p.y, p.z], [q.x, q.y, q.z, q.w])
fluids.update(dt)
view.update(dt)

innerOffset is the offset, in the bound object's space, of the origin of the container shape (the inner bottom centre). The transform given to fluids.setTransform must be that point's world position and the object's world rotation. Objects are assumed to have uniform scale.

Destroying a container's object (for example from @adatechnology/game-destruction): call view.unbindContainer(id) and fluids.removeContainer(id); the stains already on the floor stay and dry on their own.

API

createFluidRenderer(THREE, options) returns a FluidRenderer.

Budgets: stains 24 / 48 / 96, streams 12 / 24 / 48 and particles 96 / 256 / 512 for low / medium / high. When the world has more stains than the budget, the newest are drawn.

Types exported: FluidRenderer, FluidRendererOptions, FluidRendererStats, BindOptions, FluidQuality, ThreeLib. smoothOutline(front, subdiv) is exported too (the periodic Catmull-Rom used for the stain rim).

Running film

createFilmManager(THREE, options) draws the film of @adatechnology/game-fluids (blood, old blood, bile, motor oil, fuel running down a wall or a floor) over the host's surfaces. The shader is the Fluid Standard's (thickness to colour, normals from the gradient, gloss, bile bubbles, oil and fuel iridescence, cracks where it dried thick); it is drawn transparent, so the host's own surface shows where nothing is wet. The film stays near the player: at most 6 grids of 2 x 2 m (160 x 160 cells), only within 30 m, simulated inside a millisecond budget and uploaded by the dirty rectangle (gpu: pass the WebGLRenderer so copyTextureToTexture can be used). A grid that is out of range, still for 20 s or squeezed out by a newer one is baked into the stain decals of the fluid world (fluids.splash with the film's colours) and freed.

const film = createFilmManager(THREE, { scene, camera, random: createFilmLcg(1), fluids, gpu: renderer })
film.launch({ fluid: 'blood', point: [0, 1.2, 0], velocity: [1, -1, 0], radius: 4 }) // a drop; the grid is made under it
film.drip({ fluid: 'fuel', point: [0, 0.9, 0], every: 0.5 })
const bridge = createFilmBridge({ fluids, manager: film, random })
// every frame: fluids.update(dt); bridge.update(dt); film.update(dt)
bridge.splat({ fluid: 'blood', point, direction, tint: { fresh: 0x8a0a0a, dry: 0x3a1c12 } }) // a wound, in the colours of an infection age
bridge.setWeather({ rain: 1 }) // the rain hook: drying stops, spread x1.5 (a no-op until game-weather drives it)

surfaceAt(point) gives the floor, the wall and the curb of a point (layoutFromSurfaces); without it the film lies on the ground. A leak of a liquid that has a film drips from the hole into it until the stream ends.

Português

Renderizador three.js do @adatechnology/game-fluids: o líquido dentro do recipiente (um volume cortado pelo plano da superfície, sempre horizontal no mundo), fios de líquido com gota na ponta, manchas que crescem a partir de uma frente de fluxo (nunca um disco perfeito), brilho de superfície molhada que reflete o cenário e seca da borda para dentro, vapor e gotas de respingo. Só lê o estado da simulação, então é igual em LAN.

const view = createFluidRenderer(THREE, { scene, fluids, quality: 'medium', envMap })
view.bindContainer('copo', objetoDoCopo, { innerOffset: [0, 0.005, 0] })
// a cada frame: fluids.setTransform(...); fluids.update(dt); view.update(dt)