Lightning
Lightning mode turns a 3D particle into a lightning bolt. Each particle becomes a jagged bolt made of copies of the emitter's RenderPart. You get zig-zags, branches, crackle, growing strikes, and bolts that hit surfaces. Everything is still driven by the same emitter, so Rate, Lifetime, EmitCount and the graph editor work as usual.
Turning it on
- Select a 3D particle emitter (or Transform a part into one).
- In Properties, open the Lightning section and switch on Lightning.
- Emit it. Each particle is now a bolt shooting out along the emitter's direction.
Once Lightning is on, the Properties window hides the settings that don't apply to a bolt (Size, Speed, Rotation, Acceleration, Flipbook, Nested and so on). The bolt settings appear inside the normal sections, so you'll find them where you'd expect: thickness under Appearance, growth under Emission, zig-zag shape under Shape.
What the bolt is made of
Every segment of the bolt is a copy of the RenderPart, so its material, colour and transparency decide how the bolt looks. A Neon part with high LightEmission gives the classic glowing bolt. A Highlight inside the RenderPart is applied once per bolt, not once per segment. Roblox shows about 31 Highlights at a time, so very large numbers of highlighted bolts will drop some outlines.
Where the bolt strikes
The bolt's target comes from the Particles → Route setting:
| Route | The bolt... |
|---|---|
| Default | Shoots straight along the emitter's direction for Length studs. |
| Center | Strikes the emitter's centre. |
| Custom | Strikes one of your custom targets. |
With Custom and RoutePick = InOrder, the bolt instead becomes a path through every target in order, like a chain of lightning hopping between points. RouteSmooth rounds off the corners between targets.
Striking surfaces
Turn on Collision → StrikeSurface (Default route only) for ground and wall strikes. When a bolt spawns, it checks for a surface within its Length along its direction. If it finds one, the bolt ends exactly on that surface and stays attached to the part it hit. If nothing is in range, that bolt doesn't fire at all. Point the emitter down for lightning that hits the ground.
Plain Collisions also works: the bolt and its branches stop at the first surface they touch.
Property reference
Lightning section
| Property | Meaning |
|---|---|
| Lightning | The on/off toggle. Turns each 3D particle into a bolt. |
| Style | How the bolt moves. Jitter snaps to a new random shape (classic lightning). Scroll sends a smooth wave flowing along it (energy beam). JitterScroll does both. |
| JitterRate | How many times per second the bolt snaps to a new shape (graph). 10-20 crackles, 30+ is frantic, 0 freezes it. In Scroll it only re-rolls the branches. |
| ScrollSpeed | Scroll styles. How fast the wiggle travels along the bolt, in waves per second. Negative flows the other way. |
| Waves | Scroll styles. How many wiggles fit along the bolt. |
| ForkChance | How often branches split off (0 to 1). 0 = none, 0.3 = a few, 0.8 = lots. |
| ForkDepth | 1 = branches come off the main bolt. 2 = branches grow their own smaller branches too. |
| ForkLength | Branch size compared to what it grows from (0.4 = 40%). Branches are thinner and calmer by the same amount. |
| EditableMesh | Draws each bolt as one EditableMesh instead of one part per segment. Far fewer parts and much faster with lots of bolts. Off by default. |
ForkDepth and ForkLength only show once ForkChance is above 0.
EditableMesh mode
EditableMesh bolts use Color, Gradient, Transparency, Material, Width and Highlight, but ignore meshes and decals on the RenderPart. In a published game, EditableMesh only works if the game owner is ID-verified and has Enable Mesh / Image APIs turned on in the Creator Dashboard. If it isn't available (or the device is low on memory), bolts quietly fall back to normal segment parts, so it's always safe to turn on.
Appearance
| Property | Meaning |
|---|---|
| Gradient | Colour from the source (left) to the tip (right). Multiplies with Color, so leave it white to just use Color. |
| Width | Bolt thickness in studs, over the bolt's life. 0.1-0.3 is a normal bolt. Pull the end down to fade it out thin. |
| WidthAlong | Thickness from source to tip. Ending around 0.2-0.4 gives the classic tapered bolt. |
| ZOffset | Pushes the bolt toward or away from the camera, same as on normal particles. |
Color, Transparency, LightEmission and the other Appearance channels apply to the bolt as normal.
Emission
| Property | Meaning |
|---|---|
| GrowthTime | Seconds for the bolt to shoot out to full length. 0 = instant, 0.05 = snappy strike, 0.3+ = slow crawl. Negative grows from the tip back to the source. |
Rate, Lifetime, EmitCount, EmitDelay and EmitDuration work as they do for any 3D particle.
Shape
| Property | Meaning |
|---|---|
| Segments | How many straight pieces make up the bolt. More = finer zig-zags (and more parts). 16-24 suits most bolts. Enter two numbers (e.g. 12, 28) to give every bolt a random count in that range. |
| Amplitude | How far the bolt zig-zags sideways, as a fraction of its length (0.15 = 15%). 0 = straight line, 0.1-0.25 reads as lightning. |
| Roughness | How crinkly the zig-zag is at small scale (0 to 1). Low = one big smooth bend, high = rough all the way down. 0.4-0.6 looks natural. |
| StartFree | Lets the bolt's start wander (0 to 1). 0 = locked to the emitter. |
| EndFree | Lets the bolt's end wander (0 to 1). 0 = locked to its target, 0.5-1 gives a loose, searching tip. |
| Sag | Makes the bolt droop like a hanging cable, as a fraction of its length. Negative arches it upward. |
| SagShape | Shape of the droop. 1 = smooth curve, higher = pointier dip, 0.5 = round arc, 0 = flat bottom. Shows once Sag isn't 0. |
Other sections
| Section | What works on a bolt |
|---|---|
| Particles | Length: how far the bolt reaches in studs on the Default route (graph). Route, RoutePick, RouteSmooth pick the target (see above). |
| Placement | Position offsets where the bolt starts. |
| Bezier | Bezier + Radius bow the whole bolt into a curve. |
| Collision | Collisions stops the bolt at the first surface. StrikeSurface is described above. |
| Optimization | StepRate, CullOffscreen, CullDistance and DistanceLOD all apply to bolts. |
Quick recipes
- Classic strike: Style Jitter, JitterRate 15, Amplitude 0.15, Roughness 0.5, ForkChance 0.3, GrowthTime 0.05, WidthAlong tapering to 0.3.
- Ground strike: point the emitter down, Route Default, Length 40, turn on StrikeSurface.
- Energy beam: Style Scroll, Waves 3, ScrollSpeed 2, ForkChance 0, Amplitude 0.08.
- Chain lightning: Route Custom, RoutePick InOrder, add your targets, RouteSmooth 0.3.
- Hanging arc: Sag 0.2, SagShape 1, EndFree 0, low Roughness.
- Lightning storm: high Rate, Segments
12, 28, and EditableMesh on to keep the part count down.
Previewing with Paths
With Paths on, a lightning emitter draws its route plus a frozen sample of the actual bolt (zig-zags, sag, branches and all), one line for each bolt that would be alive at once. It's a quick way to tune Segments, Amplitude and the route without emitting.
Tools
Retimer, Resizer, Shifter and Copier all understand lightning emitters. Retimer scales JitterRate, ScrollSpeed and GrowthTime, Resizer scales Width and Length, and Shifter and Copier list the bolt settings.
Related
- 3D particle - the emitter Lightning mode is built on.
- Paths - preview the bolt shape.
- Graph editor - shape Width, Amplitude, JitterRate and more over life.