Skip to content

Line and Curve Modes

🇬🇧 English | 🇺🇦 Українська

The mode determines which engine components the generated meshes end up in, and whether they bend along the curve.

Global Actor Mode (Mode, ESPUsingSpawnMode)

Value Effect
Use Concrete Mode in Mesh Configuration each mesh entry decides for itself via its own Mode field (default value).
Line all entries — straight instances in an InstancedStaticMeshComponent. Best performance.
Curve all entries — separate SplineMeshComponents that bend along the curve.
Visible Only Spline nothing is created — only the spline. Handy for debugging the shape; actors along the spline don't appear either.

Entry Mode (Mode, ESPSpawnMode)

Each entry in Static Meshes has its own Mode field: Line or Curve (default Curve). It only takes effect when the actor's global mode is Use Concrete Mode in Mesh Configuration. This lets you keep straight slabs in Line and a flexible pipe in Curve within the same construction.

Line

  • Each segment is a mesh instance at a spline point, rotated to match the spline's direction.
  • Instances of one entry with the same materials are collected into a single component and added in one batch — hundreds of meshes cost only a few draw calls.
  • The mesh doesn't bend: on curved sections these are straight pieces rotated along the curve.
  • Vertical Align, full Additional Rotation, Flip X / Flip Y are available.
  • The instance's pivot is the segment's center (segment start + half the mesh length + X offset).

Curve

  • Each segment is a separate SplineMeshComponent that deforms the mesh between the segment's start and end.
  • The mesh follows the curve's bend — suitable for pipes, rails, handrails, roads on turns.
  • Additional Scale X stretches the mesh along the spline; Y and Z scale the cross-section, also accounting for the spline point scale at the segment's start and end.
  • Additional Rotation is Roll only; Twist Amount twists the mesh around the curve.
  • The number of components grows fast: 200 segments = 200 components.
  • For a smooth result the mesh needs enough detail along the X axis (several edge loops), otherwise it bends "faceted".

Which to Choose

Situation Mode
Straight elements, fences, posts, sleepers, most scenes Line
The mesh needs to bend along the curve (pipes, rails, road surface) Curve
Mixed construction Use Concrete Mode in Mesh Configuration + Mode on entries
Large final construction either mode + Merge to Static Mesh + Nanite

See Also