Fire (unstable=2)

Introduction

The Fire effect (unstable=2) simulates a realistic flame running along the blade. Unlike Classic Unstable, Fire has a clear direction. Heat starts near the base, travels upward toward the tip, and fades as it climbs.

That gives Fire a very different personality. Instead of full-blade chaos, it looks like a torch or flame sword with a visible source and a natural flow.

Classic Unstable vs. Fire

Enabling Fire

In your blade profile, set:

unstable=2

How Fire Works

Fire runs a three-step cellular simulation every frame.

1. Cool — each pixel loses heat. The maximum cooling scales with blade length, which helps preserve a natural flame height.
2. Drift up — heat from each pixel is averaged and shifted upward, creating the rising flame motion.
3. Spark — a single new spark can ignite in the lower spark zone defined by sparkd.

After that, the resulting heat map is translated into visible blade color by the same mapping system used by other unstable effects.

Core Parameters

hcool — High Cooling

Default: 70

This is the maximum cooling intensity. In Fire mode, it scales with blade length. That means the same value behaves differently on a short blade versus a long blade.

Short blades effectively cool more aggressively per pixel, so they need lower hcool values to reach the same visible flame height.

lcool — Low Cooling

Default: 20

This is the minimum cooling per frame. Unlike hcool, it is applied directly and does not scale with blade length.

Tip: For Fire, keeping lcool relatively low, often between 5 and 20, usually gives the best range of flame variation.

sparkf — Sparking Force

Default: 120

This controls how often a new spark appears. Higher values mean more frequent ignition and a brighter, more active base.

sparkd — Spark Density / Spark Zone

Default: 10

In Fire mode, this does not mean density across the whole blade like it does in Classic Unstable. Here it defines the spark zone as a percentage of blade length measured from the base.

Note: Even with sparkd=100, Fire still only generates one spark per frame. So it never behaves exactly like Classic Unstable.

Drift Mode

drift — Reverse Fire Direction

Default: 0

In Fire mode, drift works very differently than in Classic Unstable. Here it reverses the heat array so the fire starts from the tip and flows downward.

drift=0    # normal fire, base to tip
drift=1    # reversed fire, tip to base

This is useful for inverted flame looks, dripping energy effects, or deliberately unnatural fire behavior.

Caution: If you notice odd visual interactions with other features while using drift=1, test the same setup with drift=0 to confirm whether the reverse mode is the cause.

Reactivity / Mapping

mapping_unstable — Reactivity Source

Default: 1

mapping_unstable=0 — None

The fire burns with only the parameters you set. No external input changes it.

mapping_unstable=1 — Audio

The fire reacts to sound volume. Loud moments reduce cooling and increase sparking, so the fire grows taller and more chaotic during motion, clashes, and hum peaks.

Use mapping_audio=low,high to fine-tune the response range.

mapping_unstable=2 — Angular

The fire reacts to blade tilt angle.

• Tip pointed up gives lower cooling and a taller flame
• Tip pointed down gives higher cooling and a shorter flame

This produces a very intuitive result. Raise the blade and the fire grows. Lower it and the fire shrinks.

mapping_unstable=4 — Angular Reversed

This flips the angular behavior.

• Tip pointed up gives a shorter flame
• Tip pointed down gives a taller flame

This can be handy for reversed installs or if you want the opposite visual behavior.

Tip: Angular mapping is one of Fire’s best looks. It can make the blade feel physically alive instead of just animated.

Color Controls

Fire uses the same general color mapping system as the other unstable effects.

ecolor — Effect Color

This is the color used in hot and bright areas. Warm colors usually work best for Fire.

ecolor=1023,400,0,0     # orange
ecolor=1023,0,0,0       # red
ecolor=1023,720,200,0   # golden
ecolor=400,0,1023,0     # purple fantasy fire

On CFX, color channel values can go up to 1023.

mapping_color — Color Mapping Mode

For realistic fire, mapping_color=1 is usually the best choice.

mapc — Color Mapping Strength

Default: 50

This controls how strongly the effect color influences the visible blade.

mapb — Brightness Mapping Strength

Default: 50

This controls how strongly heat values affect brightness, giving more or less contrast between cool and hot regions.

Refresh Rate

refreshfx — Effect Refresh Interval

Default: 12 ms

Because Fire has directional movement, the refresh rate noticeably changes how fast the flame seems to climb.

Putting It All Together: Recipes

Recipe 1: Classic Torch

A balanced, natural-looking flame and a very good starting point.

unstable=2
sparkf=120
sparkd=10
hcool=70
lcool=20
drift=0
mapping_color=1
mapc=150
mapb=180
mapping_unstable=1
ecolor=1023,480,0,0

Recipe 2: Angry Inferno

A tall, aggressive flame that fills most of the blade. Best with audio reactivity.

unstable=2
sparkf=200
sparkd=30
hcool=40
lcool=5
drift=0
mapping_color=1
mapc=200
mapb=220
mapping_unstable=1
ecolor=1023,320,0,0
refreshfx=8

Recipe 3: Candle Flame

A small, delicate flame. This works especially well with angular mapping so the flame grows and shrinks when you tilt the blade.

unstable=2
sparkf=80
sparkd=5
hcool=150
lcool=30
drift=0
mapping_color=1
mapc=120
mapb=150
mapping_unstable=2
ecolor=1023,640,160,0
refreshfx=15

Recipe 4: Inverted Drip Fire

Fire flowing downward from the tip like dripping molten energy.

unstable=2
sparkf=140
sparkd=10
hcool=60
lcool=10
drift=1
mapping_color=1
mapc=180
mapb=200
mapping_unstable=1
ecolor=1023,200,0,0

Recipe 5: Darksaber Flame

A monochrome fire look using Legacy color mapping. This works nicely with a very dark base blade color.

unstable=2
sparkf=150
sparkd=15
hcool=80
lcool=15
drift=0
mapping_color=0
mapc=200
mapb=230
mapping_unstable=1
ecolor=1023,1023,1023,0

Recipe 6: Slow Lava Blade

A heavy, molten look with slower motion and deep glowing heat.

unstable=2
sparkf=100
sparkd=20
hcool=50
lcool=10
drift=0
mapping_color=1
mapc=180
mapb=160
mapping_unstable=0
ecolor=1023,240,0,0
refreshfx=40

Quick Reference Card

Tuning Tips

1. Blade length matters more for Fire than for most other unstable effects. If you change blade length, expect to retune hcool.
2. Start with mapping_color=1. Fire usually looks best with heat-map style color progression.
3. Use sparkd to control flame width, not flame height. Height mainly comes from the balance between sparking and cooling.
4. Angular mapping is one of Fire’s best features. It can make the blade feel physically responsive instead of just animated.
5. drift=1 is dramatic. Use it intentionally for inverted flame looks, not as a tiny tweak.
6. For ember or dying-fire looks, combine high hcool, low sparkf, and a slower refreshfx.

Crystal Focus X firmware guide · Unstable Effects Collection · Part 2 — Fire (unstable=2)