Fireplace Screensaver Simulator

Scene load{{ resultsReady ? `${formatNumber(computation.values.scene_load)}%` : '—' }} Particles{{ resultsReady ? formatCount(computation.values.estimated_particles) : '—' }} Frame budget{{ resultsReady ? `${formatNumber(computation.values.frame_budget_ms)} ms` : '—' }}

Canvas rendering is unavailable in this browser.

Theme:

Sets the full scene palette without changing the load model.

Flame intensity:

{{ displayInput('flame_intensity') }}%

Use a lower value for a quiet hearth and a higher value for a brighter focal scene.

Ember rate:

{{ formatNumber(displayInput('ember_rate')) }}×

A multiplier from 0 to 3 for rising ember density.

Smoke amount:

{{ formatNumber(displayInput('smoke_amount')) }}×

Keep smoke low when the display must preserve crisp edges or nearby text.

Wind drift:

Center the slider for a vertical flame.

Frame rate:

Log style:

Choose the base silhouette under the particle field.

{{ field.label }}:

{{ toggle.label }}:

Trail fade:

From 4 to 36 frames; higher values leave softer trails.

frames

Scene seed:

A whole number from 1 to 2,147,483,646.

Layer	Status	Tuning note	Copy
{{ note.label }}	{{ note.status }}	{{ note.advice }}

The chart renderer is unavailable. The same layer scores remain available in the settings ledger.

Setting	Value	Scene effect	Copy
{{ row.label }}	{{ row.display }}	{{ row.detail }}

An ambient fireplace is built from repeated visual cues rather than real heat or combustion. The eye reads a flame shape rising from a log bed, small bright embers, slower smoke, and a pool of warm light as one familiar scene. The illusion works best when those cues move at different speeds and do not all demand attention at once.

Fire intensity and visual busyness are related but not identical. A tall bright flame can be simple when smoke and sparks are restrained. A low fire can still feel restless when flicker, embers, crackle bursts, and drifting particles are all strong. The viewing setting decides which balance is useful.

Fireplace scene choices and their practical effects
Viewing need	Favour	Watch for
Quiet background	Moderate flame size, low flicker, few sparks, restrained smoke	Bright bursts that keep pulling attention back to the screen
Strong focal display	Higher flame intensity, wider glow, more ember activity	Washed-out edges and excessive movement at fullscreen size
Content backdrop	Low smoke and reflection, stable contrast, modest drift	Haze or glow reducing subtitle and text readability
Longer session	Lower brightness, calmer motion, device sleep and panel-care settings	Treating animation as protection against image retention or burn-in

Frame rate changes motion cadence, not the artistic settings themselves. A target of 60 frames per second asks the browser and display to draw more often than 30 FPS. Fullscreen size, device load, pixel density, and other active tabs can change the delivered rate even when the same scene profile is used.

A scene seed makes the starting particle sequence repeatable. Resetting with the same seed and settings rebuilds the same bounded sequence, which helps compare two display sizes or performance runs. Timing and the live particle population can still diverge as frames are delivered, so the seed is a comparison aid rather than a recorded video.

Comfort is personal. Strong flicker, fast particles, high contrast, or prolonged motion may be unpleasant for some viewers. A short preview cannot establish comfort for a long session, and a moving fire scene is not a substitute for the display maker's brightness, sleep, and panel-care guidance.

How to Use This Tool:

Shape the main flame first, add secondary particles sparingly, then test the applied profile at the intended size.

Choose Theme and Log style for the palette and base silhouette. These choices change appearance without changing the scene-load formula.
Set Flame intensity, Flame height, and Flame width. Add Wind drift and Flicker strength only after the main shape reads clearly.
Tune Ember rate, Smoke amount, and Spark rate. Use Hearth notes to catch a particle field that is too sparse or too busy for the selected flame.
Add glow, room reflection, heat shimmer, ambient particles, or crackle bursts when they serve the viewing setting. These details raise atmosphere or motion even when the flame shape stays unchanged.
Choose 30, 45, or 60 FPS and a trail fade from 4 to 36 frames. Start the scene, watch the measured FPS, and run a fullscreen check before settling on a profile.
If controls change while the scene is running or paused, use the restart action to apply the queued settings. Use the same Scene seed when comparing profiles under the same browser and display conditions.

Interpreting Results:

Hearth notes judges three practical balances: flame posture, particle activity, and room ambience. A warning is a tuning suggestion based on the declared scene model, not a measurement of real combustion, eye safety, heat, or display health.

Scene load summarizes configured visual intensity. Calm is below 40%, Balanced is 40% to below 70%, and Cinematic is 70% or higher.
Burn chart separates flame, particle, ambience, and motion scores so one strong effect does not hide behind the total.
Measured FPS reflects the current run. Compare it with the selected target after the scene has been active for several seconds and again in fullscreen.

Do not read a Balanced label as proof that the scene will be comfortable or smooth on every device. Lower the heaviest settings when measured delivery falls short, text loses contrast, or motion feels distracting.

Technical Details:

The fireplace is a seeded particle field drawn on a browser canvas. Flame, ember, smoke, and spark particles have different lifetimes, velocities, opacity changes, and spawn rates. A run freezes the current valid settings; edits made during playback remain queued until the scene is restarted.

Mechanism Core

Fireplace scene mechanism
Part	Mechanism	Main controls
Flame envelope	Particle height, width, density, and sideways drift form the central fire shape.	Intensity, height, width, wind, flicker
Particulate field	Embers, sparks, smoke, and optional bursts add slower and faster detail around the flame.	Ember rate, spark rate, smoke, crackle bursts
Ambient light	Glow and room reflection change the surrounding colour field without measuring real light output.	Glow, room reflection, theme
Run cadence	The chosen FPS sets the minimum frame interval. Reduced-motion preference limits live animation to at most 15 FPS.	Frame rate, trail fade
Repeatability	A seeded pseudo-random sequence initializes particles. Reset returns to that seed with the applied profile.	Scene seed

Formula Core

Scene load is a repo-authored visual-tuning index. It combines four normalized scores; it is not CPU usage or a scientific comfort scale.

L_{scene} = 0.35 L_{flame} + 0.25 L_{particles} + 0.20 L_{ambience} + 0.20 L_{motion}

The component scores are built from the visible settings before the weighted total is calculated.

Fireplace scene-load component formulas
Quantity	Exact rule
Structure	(flame height + flame width) / 2
Combustion	flame intensity + flicker + 0.45 × absolute wind
Particulate	spark rate + ember rate + 0.55 when crackle bursts are on
Flame score	50 × structure / 200 + 50 × combustion / 245
Particle score	the lesser of 100 and 70 × particulate / 6.55 + 30 × smoke / 3
Ambience score	(glow + room reflection) / 2
Motion score	0.55 × flicker + 0.25 × absolute wind + 20 when heat shimmer is on
Frame budget	1000 / selected FPS, in milliseconds

The displayed scene load and component scores are formatted to one decimal place, while the model retains full numeric precision. Estimated active particles are rounded to a whole count and capped at 500.

Rule Core

Fireplace scene-load bands and tuning rules
Result	Boundary or trigger	Meaning
Calm	Scene load < 40	Low configured visual intensity
Balanced	40 ≤ scene load < 70	Moderate configured visual intensity
Cinematic	Scene load ≥ 70	High configured visual intensity
Reduce flame posture	Structure > 150 or combustion > 182	Flame geometry or motion is high for a quiet focal scene
Reduce particles	Particulate > 3.4 or smoke > 1.9	Haze and particle activity may obscure nearby detail
Reduce ambience	Room reflection > 72 and glow > 70	The surrounding light field may look washed out

Display and Motion Notes:

The scene runs locally and does not upload a profile. Rendering quality still depends on the browser, canvas size, device pixel ratio, available processing time, and display refresh behaviour.

Pause the scene if flicker or motion causes discomfort. A reduced-motion preference lowers the live cadence but does not remove every visual change.
Use device brightness, sleep timers, pixel shifting, and other panel-care features for display protection.
The simulation has no audio, heat, combustion measurement, or physical-fire safety meaning.
Measured FPS is a short browser observation and may change when the window size or device load changes.

Worked Examples:

Subtle background beside text

Start with moderate flame intensity, low smoke, centred wind, and little or no reflection. If Hearth notes reports excessive particles or the text edge looks soft in fullscreen, lower smoke and spark rate before reducing the main flame.

Comparing 45 FPS and 60 FPS

Keep the same seed and all artistic settings, run the 45 FPS profile, then repeat at 60 FPS. The scene-load score stays the same because FPS is not part of that weighted index, but frame budget changes from about 22.2 ms to 16.7 ms. Prefer the higher target only when measured delivery remains close enough at the intended display size.