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A fireplace screensaver is a moving ambient scene meant to keep a display visually active while creating a calmer backdrop than a static wallpaper. The practical tradeoff is between atmosphere and device load: richer flame motion feels more lifelike, but it also asks more from the browser and the display.
This simulator turns that tradeoff into something you can tune directly. It renders a live canvas-based hearth with adjustable flame, embers, smoke, wind drift, glow, and particle layers, then reports runtime signals such as active particle counts, measured frame rate, quality scaling, canvas size, and fullscreen state.
That makes it useful for a quiet desk display, a reception monitor, a kiosk-style ambience panel, or a second screen that needs soft motion instead of a bright looping video. You can start with a balanced preset, push it toward dramatic flame behavior, then decide whether the effect still looks smooth enough for the hardware in front of you.
The package is deliberately visual. It does not generate heat, play fire audio, or model real combustion. Its tuning notes are aesthetic heuristics that help you judge scene density and comfort, not measurements of fuel burn or room safety.
It is also worth separating ambience from panel care. A moving scene is gentler than leaving a fixed, high-contrast image on screen for long stretches, but it is still sensible to rely on your device's sleep and display-care settings for unattended sessions.
The defaults are a sensible starting point because they sit near the tool's middle ground: visible flame motion, modest smoke, moderate glow, and a 45 FPS target. Start there, watch the measured frame rate for a few seconds, and only then decide whether you want more drama or less visual noise.
For background ambience, subtlety usually wins. Moderate flame height and width, a restrained ember rate, and smoke below the upper end of the scale tend to read better from across a room and are less likely to distract from nearby text, calls, or presentations. If the scene is meant to sit behind other work, keep an eye on Measured FPS and Quality scale rather than judging by flame brightness alone.
For a more theatrical hearth, increase flame height, width, flicker, glow, and spark rate together rather than pushing only one control to an extreme. The simulator's note panel is useful here because it calls out when the fire posture becomes oversized, when particle density becomes noisy, or when room reflection and glow start washing the scene out.
The simulator is less appropriate when you need synchronized sound, a timer that shuts the scene down automatically, or a physically grounded fire model. It is best understood as a local visual ambience tool with performance feedback, not as a media player or a thermal simulation.
The hearth is drawn on a single canvas and advanced with requestAnimationFrame. Each frame fades the previous image by an amount derived from Trail fade and flame intensity, then layers optional dust, smoke, flame particles, embers, sparks, heat shimmer, and the selected log arrangement. Because the loop only runs in the preview view, the simulator stops rendering when you switch to a non-preview tab and also pauses while the document is hidden.
Most controls are normalized into bounded numeric ranges before drawing begins. Flame intensity, glow, room reflection, and flicker clamp to 0 through 100. Ember rate, smoke amount, and spark rate clamp to 0 through 3. Flame height and flame width clamp to 50% through 200%, wind runs from -100 through 100, trail persistence spans 4 through 36 frames, and the frame-rate selector resolves to a 30, 45, or 60 FPS target.
Particle spawning scales with both the chosen settings and the current quality factor. Stronger flame intensity raises the flame emission accumulator, ember and spark controls increase their own particle streams, smoke adds slower translucent plumes, and wind bends nearly every moving layer sideways. When measured performance drops too far below the target frame rate, the script reduces internal rendering scale to protect smoothness, then restores that scale when headroom returns.
The Hearth Notes panel is not a generic tip sheet. It is driven by three package-specific heuristics that summarize flame posture, particulate load, and room mood. Those heuristics are helpful because they convert many sliders and toggles into a shorter set of decisions about comfort, readability, and scene balance.
The tuning-note heuristics use these derived signals.
| Signal | Threshold | Resulting Advice |
|---|---|---|
| Flame posture | structure load > 150 or combustion load > 182 |
Set flame posture because the scene is becoming theatrical and may feel tiring in long sessions. |
| Flame posture | structure load < 85 and flame intensity < 40 |
Strengthen core flame because the hearth may read as too weak or visually distant. |
| Particle noise | particulate load > 3.4 or smoke amount > 1.9 |
Control ember noise to protect readability and keep the scene from feeling crowded. |
| Particle noise | particulate load < 1.2 and smoke amount < 0.5 |
Add crackle detail when the fire feels too sparse. |
| Room mood | room reflection > 72 and glow > 70 |
Lower room bounce because the background can start to look washed out. |
| Room mood | heat shimmer off and room reflection < 30 |
Enrich room mood to restore warmth cues. |
| Behavior | What The Package Does | Why It Matters |
|---|---|---|
| Adaptive quality | The internal quality scale falls as low as 62% when measured FPS drops below 72% of target, and climbs back toward 100% when performance recovers. | A lower Quality scale means the simulator is preserving smoothness by reducing rendering density. |
| Visibility handling | The render loop stops when the document becomes hidden and resumes only when the preview is active again. | This prevents wasted work in background tabs and keeps measured FPS readings more meaningful. |
| Canvas sizing | The preview canvas snaps to the preview pane or fullscreen surface with a minimum CSS size of 320 by 220. | Larger canvases need more particles and more fill work, which can change the feel of the same preset. |
| Local execution | Rendering, metrics, exports, and clipboard actions all happen in the browser. The tool ships no server helper. | Your scene settings stay on the device unless you deliberately copy or download them. |
The summary line tells you whether the animation is currently running, while the metrics table explains what the simulator is doing under the hood. Target FPS is the requested cadence, Measured FPS is the delivered cadence, and Quality scale shows whether the tool has started lowering internal render density to keep motion smooth.
The active particle counts are workload indicators, not quality scores. A high number of flames, embers, smoke plumes, or sparks only means the scene is busy. It does not mean the fire looks better, and it can make the background harder to live with during long sessions.
The Hearth Notes priorities are best read as editing cues. P1 addresses flame posture, P2 addresses particle noise, and P3 addresses room mood. When those notes conflict with your visual impression, trust the preview first, then use the note that matches the problem you actually see.
The easiest false-confidence trap is to judge a preset only by how attractive it looks in a still moment. Before settling on it, verify that Measured FPS remains healthy, that Quality scale is not pinned low, and that the scene still feels balanced when the canvas is larger or fullscreen.
Set the theme to Classic, use flame intensity 50, ember rate 0.60, smoke amount 0.40, spark rate 0.30, glow 45, room reflection 30, flame height 95%, flame width 90%, flicker 40, and keep heat shimmer on. Those values keep structure load and particulate load in the middle of the range, so the preview usually reads as steady ambience instead of a dramatic focal point.
Switch to Sunset, raise flame intensity to 85, ember rate to 1.80, smoke amount to 1.60, spark rate to 1.50, glow to 75, room reflection to 78, flame height to 160%, flame width to 150%, flicker to 70, and add a little wind. In that zone the note panel will warn about flame posture, particle noise, and room bounce. That is expected. The point of the preset is spectacle, so the real question becomes whether your hardware can hold the target frame rate without dragging quality scale down too far.
If you choose 60 FPS, enlarge the preview, and also push smoke, spark, ember, and ambient particle settings upward, the simulator may start reporting a lower measured frame rate and a reduced quality scale. The corrective path is practical: lower smoke and sparks first, drop to 45 FPS if needed, then reset the scene so you can judge the result from a clean baseline.
No. The package is visual only. Crackle bursts adds extra spark particles, not sound.
Browser load, display size, fullscreen state, and other activity on the device can all change delivered frame rate. The simulator reacts by adjusting Quality scale when needed.
It means the tool has reduced internal rendering density to protect smooth motion. The scene can still look good, but it is a sign that your current preset is close to the device's comfort limit.
Moving imagery is generally kinder than a fixed high-contrast window, but it is not a guarantee against image retention or long-term panel wear. For long unattended sessions, use the display's built-in sleep and care settings as well.
No. The simulator runs in the browser, and the package does not include a server-side helper. Copies and downloads happen on the device.