Actor

The Pipe Builder actor uses a spline component to generate procedural pipe networks with full control over geometry, corners, junctions, and supports. Built in C++ for responsive editor performance.

Pipe Variables

General Variables

These variables affect nearly all generated meshes.

Thickness

Controls the overall scale/thickness of pipe meshes.

0.7

1

1.5

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Global Roll Angle

Applies uniform roll rotation to all eligible meshes.

0

25

60

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Loop Mesh Selection

Controls how segment meshes are chosen along straight pipe segments: Default is Longest Random type.

• Random: Selects a random mesh based on weighted probabilities.
• Longest: Identifies the longest available static mesh that fits within the current segment length.
• Longest Random: PSame as Longest, but shuffles the order of selected meshes to create more varied results. This resolves the “shortest mesh last” issue common with the standard Longest method. Slightly slower, but produces superior visual variety.

Random

Longest

Longest Random

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Loop Roll Rotation

Applies randomized rotation to loop segment meshes.

Rotation Methods:

• None: No rotation applied.
• Free: Random rotation between Angle Min Max values.
• Cardinal: Snaps rotation to one of four cardinal directions: 0°, 90°, 180°, or 270°.
• Flip: Randomly rotates by 180°;

Corners

The plugin offers two fundamentally different approaches to corner creation, each with distinct advantages and trade-offs.

Fitted

Bent with bend scale 1

Bent with bend scale 2.5

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Bent Corners

Deforms the spline mesh at each point, with additional control over the bend intensity.

Advantages:

• Functions reliably for angles under 90°.
• Produces smooth, continuous curvature.
• No custom static mesh assets required.

Limitations:

• UV distortion becomes noticeable beyond 90°.
• Meshes can self-intersect beyond 90°, requiring manual adjustment.
• Spline mesh updates can be slow due to Chaos Physics calculations and high vertex counts.

Fitted Corners

Places pre-modeled static meshes at spline points, selected based on corner angle and segmentation settings.

Advantages:

• Supports instancing and batching.
• Fast to compute—no physics or deformation overhead.
• Handles extreme angles cleanly without distortion.

Limitations:

• Cannot be rotated using the global roll angle.
• Requires pivot point setup in an external DCC tool.
• More time-consuming to author and maintain.

The plugin mitigates this by deferring spline mesh updates until all required variables are set, but the underlying bottleneck remains.

As shown in the Unreal Insights capture below:

Bent timings for 1 spline mesh

Bent timings

Fitted type timings

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Recommended Solution:
For any deformable corner mesh, manually set Collision Complexity to Use Simple Collision as Complex in the Static Mesh Editor.
This can dramatically improves editor responsiveness. You can revert this setting before packaging if needed.

Corner Variables

Junctions

Junctions add branches, caps, or other meshes at spline points, enable connections between pipe actors, and help create a pipe network.

Generation rules:

• Open splines: Junctions appear at start and end points
• Closed splines: Junctions appear only at the first point
• Straight segments: Junctions generate at spline points along a perfectly straight line (no corner mesh)

Junction Variables

To quickly create an inline junction, select a point, switch the gizmo to local space using Ctrl+`, then hold Alt and drag in your preferred direction. This will create an additional inline point. See the example below.

Advanced