Draw Spline Tool

Note

This is the Spline tile in the Create palette of the Meta Road editor mode (see The Meta Road Editor Mode).

The Spline tool active in the Create palette

The Draw Spline Tool lets you “draw” a URoadSplineComponent the way you would in a 2D vector editor. There are two drawing modes, chosen automatically by where you start:

Drawing from Profile — start anywhere except on a lane connection.
Drawing from Lane Successor Connection — start on an existing lane connection.

Drawing from Profile

If you start drawing from any point other than a Lane Successor Connection, the Drawing from Profile mode is selected. Pick the starting lane layout from the Draw Profile dropdown:

A new road profile can be added in Profiles.

Start Drawing from Lane Successor Connection

If you start drawing from a Lane Successor Connection, the Drawing from Lane Successor Connection mode is selected. Profiles are not available here; instead you set the number of lanes on the left and right of the source road by clicking the on-screen lane discs:

Drawing a road starting from a lane connection

Stop Drawing from Lane Predecessor Connection

You can finish a spline at a Lane Predecessor Connection — the drawing completes and you choose how to create the URoadSplineComponent (or cancel):

Finishing a spline at a lane predecessor connection

Finishing Spline Drawing

Once the spline is drawn, there are two ways to create it:

Create a new actor and add a URoadSplineComponent to it.
Add to the selected actor — a URoadSplineComponent is added to a selected actor that already contains at least one (this is how you build a junction inside a single actor).

Choosing to create a new actor or add to the selected actor

Properties

Property	Default	Description
`Draw Profile`	`2_Lanes+Borders`	The Road Profile a new road starts with (Profile mode; disabled when drawing from a connection)
`Loop`	off	Draw a closed-loop road — see Closed-Loop Splines
`Looped Road Zone`	—	Surface zone that fills the loop interior (when `Loop` is on)
`Click Offset`	20	Offset above the hit surface, cm
`Up Vector Mode`	Use Hit Normal	How the road’s up direction is derived at each point
`World Objects` / `Custom Plane` / `Ground Planes`	on / off / on	Which surfaces a click raycasts against
`Create Blueprint` / `Blueprint To Create`	off	Optionally output a Blueprint instead of a level actor

Next steps

Configure lanes in Section Mode and shape the reference line in Spline Mode.
Wire roads into junctions — see Intersections and Junctions or the Intersection Tool (Pro).
Bake to generate the mesh.