Async Spline Builder is a performance-focused tool for Unreal Engine that lets you generate and update long spline-based meshes without blocking the editor.
Instead of doing all the heavy work in a single frame, the plugin splits the generation into small batches that are processed over multiple ticks. This keeps the editor responsive while thousands of spline segments are created, updated or rebuilt.
Whether you are building race tracks, roads, tunnels, cables, rails or any other spline-driven geometry, Async Spline Builder gives you full control over how much work is done per frame – so you can finally work with long splines without staring at a frozen editor.
🔹 Key Features
Non-blocking spline generation
Long spline meshes are processed in small batches over time, so the editor stays responsive even with very large splines.Configurable batch size
Control how many spline segments are processed per tick to balance speed vs. responsiveness for your project and hardware.Supports common spline workflows
Designed to work with Unreal’s built-in spline and spline mesh components for roads, tracks, pipes, cables and other repeated geometry.Progress feedback
See how far the async build has progressed (e.g. percentage, current segment index). Ideal for very long tracks or complex meshes.Cancelable operations
Stop a long-running build if you change your mind or need to adjust settings before continuing.Editor-friendly workflow
Trigger async builds from a dedicated tool/actor or editor utility and keep working in the level while the spline is generated.C++ core with Blueprint access
The system is implemented in C++ for maximum performance and exposes a clean Blueprint API for quick integration into existing tools and levels.
🔹 Typical Use Cases
Large race tracks or rally stages with thousands of spline segments
Open-world roads and highways that need to be rebuilt frequently
Pipes, cables, rails, fences and other repeated spline-based meshes
Tools that need to update splines procedurally without blocking level designers
Any situation where a “Build Spline” button currently freezes the editor for seconds or minutes
🔹 How It Works (Technical Overview)
Async Spline Builder does not change your mesh workflow – it changes how and when the work is executed.
Instead of creating all spline mesh segments in one blocking loop, the plugin:
collects all required spline operations,
splits them into batches,
and processes a limited number of segments per frame.
This keeps the game thread responsive and gives you precise control over performance characteristics. The result is identical to a synchronous build – you just don’t have to wait with a frozen editor window.
🔹 Requirements & Compatibility
Engine: Unreal Engine 5.x
Platforms: Editor-only tool (runtime use optional, depending on your setup)
Code: C++ plugin with Blueprint-accessible functions
Tested with: UE 5.4+
🔹 Included Content
Async Spline Builder plugin (C++ source)
Example level demonstrating long spline generation
Example prototype assets and setup for a track/road use case
Quick start documentation
🔹 Support
If you encounter issues or have feature requests, feel free to reach out via the Fab support section. Feedback from level designers and technical artists is very welcome – especially for advanced workflows like racetracks, roads, or procedural world tools.