Lifetime and Speed Modules

Lifetime and speed modules are most useful in combination: the shield layers several emitters whose size, color, and motion evolve together.

Lifetime modules sample with normalized particle age. Speed modules first map current speed through a configured range. They multiply or add to the start values instead of replacing the whole particle state blindly.

Module Reference

Module	Input	Effect
Color over Lifetime	normalized age	Multiply particle color/alpha by a gradient or color function.
Size over Lifetime	normalized age	Scale X/Y/Z size.
Rotation over Lifetime	normalized age	Add roll, pitch, and yaw.
Velocity over Lifetime	normalized age	Add linear/orbital/radial velocity and speed modification.
Force over Lifetime	normalized age	Integrate acceleration into velocity.
Color by Speed	remapped speed	Multiply color according to movement speed.
Size by Speed	remapped speed	Scale size according to speed.
Rotation by Speed	remapped speed	Add rotation according to speed.
Lifetime by Emitter Speed	emitter speed	Adjust lifetime assigned at spawn.

Enable Is a Runtime Value

Animatable module enables since 2.2.0

Toggle modules expose their enable state through the emitter runtime. Timeline animation can therefore turn a module on and off without rewriting authored config.

Speed Range

By Speed modules remap the configured minimum and maximum to 0..1 before sampling their function. Keep the range representative of real particle velocity; a range far above actual speed makes the function remain near its first key.

Value Space

Vector-producing modules may expose ValueSpace. This controls whether axes are interpreted in local, world, or another supported basis. It does not change the emitter's Particle Simulation Space.

Combining Modules

Start Color × Color over Lifetime × Color by Speed produces the effective particle color before material logic. Size follows an equivalent pattern. Rotation and motion modules accumulate contributions.

When debugging:

1. Set the start value to a simple constant.
2. Enable one module.
3. Use a visible linear curve from zero to one.
4. Add the second module only after confirming the first input range.