AFM_Spline

Spline mesh components and a helper for laying meshes along a spline, used by the teleport arc and cable-like props.

What it gives you

Meshes laid along a spline with tapering
Animated extend and collapse
Colour interpolation

Requires

AFM_AutoDestroy

Required by

AFM_WidgetInteraction AFS_UI_Labels AFS_UX_Laser AFS_UX_Teleporter

2 assets26 API members

Description

AFM_Spline draws continuous geometry along a curve. Its most visible use is the teleport arc, but it works equally for cables, hoses and pointer beams.

BP_Helper_Spline manages a set of BPC_SplineMesh sections along a SplineComponent, with independent start and end radii so the shape can taper, and ShowSplinePercent for animating the curve extending towards a target.

Setup

Enable AFM_Spline.
Spawn or place a BP_Helper_Spline.
Set Radius Start, Radius End and Material.
Call SetSplineLocations to define the curve.

Usage

Animating an arc

Call SetExpand to extend or collapse over a duration, optionally destroying the actor afterwards.

Reacting to a target

Use ShowSplinePercent to reveal the curve progressively as it approaches a valid destination.

Key properties

Property When to change

Radius Start / Radius End Taper the shape

Spline Color Appearance; interpolate for state changes

Interp Speed How quickly colour and endpoint changes blend

Property	When to change
`Radius Start` / `Radius End`	Taper the shape
`Spline Color`	Appearance; interpolate for state changes
`Interp Speed`	How quickly colour and endpoint changes blend

Extending

Derive from BPC_SplineMesh for custom section behaviour.

Performance notes

Performance

Each section is a spline mesh component. Keep section counts modest on mobile; the teleport arc uses a deliberately small number.

Example map

Visible as the teleport arc in Map_Examples_Teleporter.

Troubleshooting

The spline renders as straight segments. Too few sections for the curvature — increase the section count when creating the meshes.

API reference

Every blueprint asset in this plugin. Expand an asset to see its members.

Components

BPC_SplineMesh12 members

extends SplineMeshComponent

Kind	Name	Signature	Description
var	`Color`Style	`LinearColor`	Colour written into the spline mesh material.
var	`Interp Speed`Settings	`float`	How quickly the mesh interpolates towards a new colour or end point.
var	`Scale`Style	`float`	Overall thickness multiplier for the spline mesh.
fn	`TraceAndEndPoint`	`(TraceLength: float = 1000, out Hit: HitResult)`	Traces forward along the spline direction and returns what it hit, so the spline can terminate on geometry.
fn	`UpdateEndPoint`	`(EndLocation: Vector)`	Moves the far end of the spline mesh to the given world location.
fn	`SetExpand`	`(Percent: float)`	Sets how much of the spline is drawn, from 0 for hidden to 1 for fully extended.
fn	`SetColor`	`(Value: LinearColor)`	Sets the spline's colour on its dynamic material at once, with no blend. Use the helper's animated variant instead when the change should be seen.
fn	`getWorldEndLocation`Transform	`() → Vector`	Returns the current world location of the spline's far end.
event	`InterpolateToColor`	`(ref const NewColor: LinearColor)`	Blends the spline colour towards the target over time.
event	`Expand`	`(Set: bool, Duration: float)`	Animates the spline extending or retracting over the given duration.
event	`Show`	`(Set: bool)`	Reveals the spline mesh. Passing false is ignored, so hide the mesh through the owning spline helper rather than expecting this to toggle both ways.
event	`SetSizeScale`	`(Scale: float)`	Changes the spline thickness at runtime.

Helper

BP_Helper_Spline14 members

extends Actor

Kind	Name	Signature	Description
var	`RadiusStart`Size	`Vector2D`	Cross-section radius at the start of the spline. Combine with Radius End to taper the shape.
var	`RadiusEnd`Size	`Vector2D`	Cross-section radius at the end of the spline.
var	`Spline`Spline	`SplineComponent`	The spline component the meshes are laid along.
var	`Material`Settings	`MaterialInterface`	Material applied to every generated spline mesh section.
var	`SplineColor`Color	`LinearColor`	Colour written into the spline material.
fn	`CreateSplineMeshes`Spline	`()`	Generates the mesh sections along the spline. Call after changing the spline point count.
fn	`UpdateSplineMeshes`Spline	`()`	Repositions the existing mesh sections to match the current spline shape.
fn	`ShowSplinePercent`Spline	`(Percent: float)`	Reveals the spline up to the given fraction of its length, for animating an arc extending towards a target.
fn	`SetSplineLocations`Spline	`(StartLocation: Vector, EndLocation: Vector, ForwardVector: Vector)`	Sets the spline's start and end points and the tangent direction, rebuilding the curve between them.
fn	`SetSize`Size	`(RadiusStart: Vector2D, RadiusEnd: Vector2D)`	Sets the start and end radii immediately.
fn	`InterpolateSize`Size	`(RadiusStart: Vector2D, RadiusEnd: Vector2D, DeltaTime: float, InterpolationSpeed: float)`	Blends the start and end radii towards new values over time.
fn	`InterpolateColor`Color	`(Target: LinearColor, DeltaTime: float, InterpSpeed: float)`	Blends the spline colour towards the target over time.
fn	`SetColor`Color	`(Value: LinearColor)`	Sets the colour of every mesh segment along the spline at once, with no blend.
event	`SetExpand`	`(Set: bool, Duration: float, DestroyAfterCollapse: bool)`	Animates the spline extending or collapsing, optionally destroying the actor once it has collapsed.