Trail

A Trail connects two Attachments and draws a textured streak along the path the attachments travel. Move the attachments through space, and the Trail leaves a visible wake behind. Stop moving, and the wake gradually disappears as each segment ages out.

That’s a Roblox built-in — Roblox’s Trail class does the actual drawing, the per-segment fade, the texture mapping. The plugin’s role for Trail is narrower than for the other types: it gives you a property panel that reads and writes Trail values directly, and it pulses the Trail’s Enabled flag for timed emissions. Everything you see on screen is Roblox’s native rendering of the property values you’ve set.

What it transforms

Any Roblox Trail instance with valid Attachment0 and Attachment1. The “transformation” is mostly a label change — the plugin marks the Trail as a Part-Icles emitter and starts including it in clipboard, retime, hue, and bulk-edit operations. There’s no Render Template, no PartIcleProperties Configuration child, no per-particle duplication. The Trail keeps its native Roblox properties; the plugin just gives you a nicer surface to edit them.

This is how the plugin handles the type internally: every property read goes straight to the Trail instance (trail.Color, trail.Transparency, etc.) instead of being looked up on a Configuration child. Every property write goes the same way — set it in the panel, the plugin writes it directly.

That’s the whole architectural difference. No engine path, no Heartbeat update, no clone pool.

What “emit” means for a Trail

Roblox’s native Trail behaviour: when Enabled is true, the Trail records new path segments as the attachments move. Each segment lives for Trail.Lifetime seconds, fading out over that span according to the Color and Transparency graphs. When Enabled is false, no new segments are recorded, but existing ones keep drawing until they age out.

The plugin’s “emit” for a Trail is a timed pulse of that flag. Click Emit (or call Particle:AbsoluteEmit(item)), and the plugin sets Trail.Enabled = true, waits for the parsed EmitDuration seconds, sets it back to false. The Trail draws during that window; segments born during the window keep drawing for Lifetime seconds after the window closes (the natural tail).

Particle:Emit(trail) does not fire a Trail — the per-type dispatch table inside :Emit covers Beam, PointLight, Attachment, Model, BasePart, the four screen-space types, and ImageLabel, but there is no Trail branch (Trails fall through to a silent no-op). Use Particle:AbsoluteEmit(trail) to fire a Trail emit pulse; AbsoluteEmit handles Trails through a separate path that pulses the Enabled flag the same way the panel’s Emit button does.

EmitDuration for a Trail is stored as a string. A single number ("2") is a fixed duration. A two-value string ("5,2") is parsed as a min/max range — the plugin picks a random duration between the two values per emit. The values get sorted, so "5,2" and "2,5" are equivalent — both produce a random duration somewhere between 2 and 5 seconds.

If EmitDuration parses to 0 or fails to parse at all (empty string, "abc", etc.), the emit pulse is skipped — the Trail’s Enabled flag stays at whatever it was. To fire a Trail at all you need a positive duration value.

There is no per-emit duplication. There is no per-emit randomisation of any other property — the same Trail instance pulses on and off. If you want variety between emissions, vary EmitDuration (the only randomised value) or change the property graphs between emit calls.

Properties at a glance

The full surface area, grouped by panel section. Every row writes directly to the Trail instance — no PartIcleProperties indirection.

Emission

Panel label	Data attribute	Type	Default	What it does
Enabled	Enabled (native)	boolean	true	Whether the Trail records new path segments
Lifetime	Lifetime (native)	number	2	Seconds each path segment lives before fading out
Duration	EmitDuration (attribute, string)	string	"2"	How long Enabled stays on per emit. Single number or "min,max" range

Appearance

Panel label	Data attribute	Type	Default	What it does
Texture	Texture (native)	string	from source	The image painted along the trail
Brightness	Brightness (native)	number	1	Glow multiplier — a single number, not a graph
Transparency	Transparency (native)	NumberSequence	0.5	Opacity over the segment’s life (from new to expired)
Color	Color (native)	ColorSequence	white	RGB over the segment’s life
WidthScale	WidthScale (native)	NumberSequence	1	Trail thickness over the segment’s life
LightEmission	LightEmission (native)	number	0	Self-illumination, additive blending
LightInfluence	LightInfluence (native)	number	1	How much scene lighting affects the trail

Geometry

Panel label	Data attribute	Type	Default	What it does
MinLength	MinLength (native)	number	0.1	Minimum path-segment length, in studs
MaxLength	MaxLength (native)	number	0	Maximum total trail length. 0 is unbounded
TextureLength	TextureLength (native)	number	1	How far one texture tile covers along the trail
TextureMode	TextureMode (native)	enum	Stretch	How the texture fits — Stretch, Wrap, Static
FaceCamera	FaceCamera (native)	boolean	false	Re-orient the trail’s flat side to face the camera each frame

Advanced

Panel label	Data attribute	Type	Default	What it does
PreloadTexture	PreloadTexture (attribute)	boolean	false	Force-load the texture before emit begins

That’s the entire panel. No Spawning section beyond Enabled/Lifetime/Duration, no Movement section (the trail doesn’t move — its endpoints do, and that’s outside the plugin’s control), no Advanced flag for Anim. Steps or Linger (no per-frame engine animation to sample). No GraphBlender (single Color and Transparency suffice for trails).

Per-property prose

Lifetime

How long each path segment lives before fading out. A number, not a NumberRange — the same value applies to every segment. Default is 2 seconds.

This is a different meaning from Lifetime on a Part emitter. There, Lifetime is the per-particle duration; here, it’s how long each piece of the trail persists before the engine erases it. A trail with Lifetime = 5 leaves a long, slow-fading wake. A trail with Lifetime = 0.2 leaves a short flash that disappears almost immediately.

Combined with how fast the attachments move, Lifetime controls how long the visible wake is on screen. Fast attachments + long Lifetime = a long ribbon; slow attachments + short Lifetime = a faint smudge.

Duration

The plugin-specific timing knob. A string. Single value ("2") is a fixed duration in seconds. Comma-separated pair ("5,2") is parsed as a min/max range — the plugin picks a random duration between the two numbers per emit. Order doesn’t matter ("5,2" and "2,5" produce the same range). Default is "2".

Duration controls only how long Trail.Enabled stays on per emit. After the window closes, segments born during the window keep drawing for Lifetime more seconds — that’s Roblox’s native behaviour, not part of Duration. So the visible wake outlives the emit pulse by up to Lifetime seconds.

If you want trails that pulse in bursts of varying length (a flickering laser, a stuttering thrust), set Duration to a two-value range. If you want clean uniform pulses, leave it as a single number.

Texture

The image painted along the trail. A Roblox asset id. Each segment of the trail shows a portion of the texture, mapped according to TextureMode and TextureLength. Animated textures (flipbooks) on Trails are not supported by the plugin’s flipbook system — flipbooks are a Part/Beam feature.

Brightness

A single number, not a graph. Multiplies the trail’s rendered brightness uniformly across all segments. Values above 1 make the trail glow more brightly; values below 1 dim it.

This is one of the same-name-different-shape (polymorphism) gotchas in the plugin: Brightness is a NumberSequence graph on Part, Beam, and PointLight, but a single number on Trail (and on Roblox’s ParticleEmitter). The reason is mechanical: Roblox’s Trail.Brightness is a single number property, not a NumberSequence. The plugin can’t expose a graph editor on top of a property that doesn’t have a sequence channel underneath, so it stays a single-value field. The graph editors elsewhere on Trail — Color, Transparency, WidthScale — show up because those are sequence properties on the Roblox Trail class.

Transparency

A NumberSequence for opacity over each segment’s life, from new (age 0) to expired (age 1). 0 is fully opaque; 1 is invisible.

A “fade-out” trail uses 0 at age 0 rising to 1 at age 1 — every segment starts opaque when it’s born and fades to invisibility as it ages out. This is how trails dissipate naturally instead of cutting off sharply.

Color

A ColorSequence for the tint over each segment’s life. A flame trail might go from white-yellow at birth to deep red at expiration. A magic trail might cycle through several hues.

Roblox interpolates the colour graph along each segment as it ages, drawing each piece of the trail at whatever colour the graph says at its current age.

WidthScale

A NumberSequence multiplier on the trail’s thickness, varying over each segment’s life.

A trail that narrows with age uses a graph from 1 at age 0 to 0 at age 1 — segments are full width when new and pinch off to nothing as they expire. A trail that widens uses the opposite shape. Pulsing graphs produce widths that ripple along the trail.

The graph is a multiplier. The actual width comes from the source Trail’s Width property (a Roblox-native Trail property the plugin doesn’t expose in its panel). WidthScale applies on top of that base width.

These three graphs are not animated by the plugin — they’re stored on the Trail instance, and Roblox renders them as the Trail draws. The plugin’s role is to give you a graph editor that writes these values directly to Trail.Color, Trail.Transparency, Trail.WidthScale.

LightEmission

A single number, not a graph. Additive-blending strength. 0 is normal blending; 1 is fully self-illuminated. Useful for laser, magic, or thrust trails where the streak should appear to be a light source.

LightInfluence

A single number. Scene-lighting integration: 0 ignores scene lighting (the trail always renders at its base brightness); 1 integrates fully (the trail dims in shadows).

Trail’s default differs from Beam’s: LightInfluence is 1 by default (integrates with lighting), and the plugin doesn’t force it to 0 like it does for Beam. Reason: trails often should respect scene lighting — a real-world trail of dust or fog reads more naturally when shadowed by other geometry. If you want a self-illuminated trail anyway, set this to 0.

MinLength

The smallest distance the attachments must travel before the engine creates a new path segment, in studs. Smaller values mean smoother trails at the cost of more segments. Larger values mean choppier trails with fewer segments.

Default is 0.1. For curved or fast-moving trails, leave it low. For straight, slow-moving trails, raising it cuts segment count without much visual cost.

MaxLength

The maximum total length of the visible trail, in studs. 0 (the default) means no cap; the trail can grow as long as Lifetime × max-velocity allows.

Setting a cap is a performance lever for fast-moving attachments — without one, a missile trail at high speed could produce kilometre-long trails that pile up segments. With MaxLength = 50, the trail self-trims to fifty studs even if the attachments fly faster.

TextureLength

How far one texture tile covers along the trail, in studs. Larger values stretch each tile; smaller values pack more tiles into the same length. Combined with TextureMode = Wrap, this controls the apparent size of the texture pattern along the trail.

TextureMode

How the texture fits the trail. The same enum as Beam — Stretch, Wrap, Static.

• Stretch (the default) — the texture is scaled to fit the full trail length once. TextureLength is ignored.
• Wrap — the texture repeats along the trail, with TextureLength controlling the tile size.
• Static — the texture is anchored to the world; the trail slides through a fixed texture coordinate.

FaceCamera

A toggle. Default is false — a different default from Beam’s true. A Trail’s flat side has a fixed orientation derived from the attachments’ Up vectors, which usually reads correctly in 3D scenes without billboarding. Turn this on if your camera angle reveals the trail edge-on (which makes it disappear).

PreloadTexture

Same role as on Beam: ensures the texture is loaded before the first emit pulse begins. Useful for tightly-timed cinematic effects. Most of the time, leave it off.

Worth knowing

A few Trail-specific quirks.

Transform is a no-op for Trail. The plugin’s Transform flow doesn’t create a RenderTemplate, doesn’t create a PartIcleProperties Configuration, and doesn’t add the attribute set that other types get. It marks the Trail as a Part-Icle emitter (so the plugin recognises it for clipboard/retime/hue/bulk operations), and that’s all. The Trail keeps its native Roblox properties unchanged.

No “Animate mode” for Trail. Animate mode (covered in chapter 6) only applies to types that duplicate-and-animate. Trail doesn’t duplicate — its visual is always live, drawn by Roblox as the attachments move. The plugin doesn’t expose EmissionMode or AnimateLoop on transformed Trails because there’s no choice to make.

You can’t put a Render Template inside a Trail. Some users coming from Part ask “can I put a child instance inside the Trail and have it spawn that child as the Trail draws?” No — Roblox Trails don’t carry per-segment children. If you want trail-following-particle behaviour (each particle leaves its own short trail behind it), the setup is different: place an Attachment with a Trail inside a Part emitter’s Render Template. Each emitted Part-particle then carries its own Attachment+Trail and leaves a tiny streak. That’s covered in Hidden Depths.

Brightness, LightEmission, LightInfluence are single numbers. Easy to forget if you’re authoring from a Part-emitter mental model where these are graphs. The panel input is a number field, not a graph button — that’s the visual cue.

Lifetime here is per-segment, not per-particle. Same name as on Part, different semantics. Be careful when reading values across types — a Lifetime of 0.5 on a Part emitter means each particle lives half a second, but on a Trail it means each path segment fades over half a second.

What’s next

Trail handed control of the rendering to Roblox’s built-in Trail behaviour. The next type, PointLight, is calmer than any of the workspace types so far. No motion, no spread cone, no shape, no flipbook. Just a few colour and brightness graphs that play out over each particle’s life. Why is a light so simple compared to a particle, and what does an emitted PointLight even do?