Reference

Quality levels

Four tiers, from integrated laptop GPUs to stills and trailers. A tier sets the grid resolution, the raymarch budget, the pressure iterations and the advection scheme.

const fire = await FireSystem.create({ renderer, scene, camera, quality: 'medium' });   // 'med' works too
fire.setQualityLevel('ultra');
fire.quality;          // 'ultra'
fire.grid;             // { nx: 80, ny: 120, nz: 80, cell: 0.05 } for a 4 × 6 × 4 m domain

`campfire` on `low` (40×60×40, semi-Lagrangian) and on `high` (64×96×64, MacCormack for the scalars), from the same camera.

`campfire` on `low` (40×60×40, semi-Lagrangian) and on `high` (64×96×64, MacCormack for the scalars), from the same camera.

#At a glance

Tier	Grid (4×6×4 m domain)	Voxels	Raymarch steps	Volume res	Jacobi	Advection
`low`	40×60×40	96K	84	0.5×	12	Semi-Lagrangian
`medium`	52×78×52	211K	112	0.6×	18	MacCormack (scalars)
`high`	64×96×64	393K	140	0.85×	24	MacCormack (scalars)
`ultra`	80×120×80	768K	190	1.0×	32	MacCormack (scalars + velocity)

The volume resolution is relative to the canvas. On high-DPI screens it's capped at about 1.5× DPR pixels, and the TAA covers the rest. high is the default.

#Every field

QUALITY_LEVELS holds one object per tier:

Field	low	medium	high	ultra
`n`	40	52	64	80	Grid cells across the domain's x size. y and z follow the domain's aspect
`steps`	84	112	140	190	Raymarch steps across the domain diagonal
`scale`	0.5	0.6	0.85	1.0	Volume render resolution relative to the canvas
`jacobi`	12	18	24	32	Pressure iterations per step
`lsteps`	8	10	12	14	Light-volume steps toward the key light
`fsteps`	6	8	8	10	Light-volume steps toward the fire centroid
`maccormackState`	off	on	on	on	Second-order advection of temperature and smoke
`maccormackVelocity`	off	off	off	on	Second-order advection of velocity
`coolingScale`	1	1.9	1.9	1.9	Compensates the lower numerical diffusion of MacCormack
`smokeFade`	0.1	0.6	0.6	0.6	Smoke dissipation per second, compensated the same way
`label`	`LOW`	`MED`	`HIGH`	`ULTRA`	Display name

Fuel always uses first-order advection, even on MacCormack tiers. Its numerical diffusion is part of how the flame front is tuned, and sharpening it only makes the flames taller, not crisper.

#Custom tiers

The tiers are plain objects that are read when the grid is built. Edit one before create() or setQualityLevel():

import { QUALITY_LEVELS } from 'naturegl-fire';

QUALITY_LEVELS.high = { ...QUALITY_LEVELS.high, scale: 0.6, jacobi: 18 };   // cheaper high
fire.setQualityLevel('high');                                              // rebuild with it

#Pick a starting tier

This is a rough guide rather than a benchmark. Profile on the hardware you target.

Target	Tier
Integrated GPUs, phones	`low`
Mid-range laptops	`medium`
Apple M-series, discrete desktop GPUs at 1080p–1440p	`high`
Stills, trailers, posters	`ultra`

The cost is mostly the grid (voxels × Jacobi iterations) plus the raymarch (screen pixels × scale² × steps). A smaller domain at the same n looks sharper for the same cost. The demo drops a tier by itself when it averages under 28 fps at start-up. Copy that logic from demo/main.js if you want the same thing.