[Feature Request] Configurable Construction Script Preview Update Rate / Throttling

General Feedback & Requests
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[Feature Request] Configurable Construction Script Preview Update Rate / Throttling

Summary

I’d like to request an optional way to throttle how often Blueprint Construction Scripts execute while editing actors in the viewport.

The current behaviour is excellent for lightweight Blueprints, but as procedural editor tools become more complex, Construction Scripts can become one of the biggest sources of editor hitching.

Current Behaviour

Currently developers effectively have two choices:

  • Run Construction Script on Drag enabled

    • Provides excellent live feedback.

    • Can execute dozens of times per second while dragging.

    • Heavy procedural actors can cause significant editor stutter.

  • Run Construction Script on Drag disabled

    • Smooth editor performance.

    • Loses the live incremental preview that makes procedural tools enjoyable to use.

There is no middle ground.

Example Use Cases

This would benefit many procedural Blueprint tools, including:

  • Roads

  • Splines

  • Fences

  • Modular building generators

  • Dungeon generators

  • PCG helper actors

  • Foliage placement tools

  • Procedural mesh generation

  • Landscape editing helpers

  • Large Instanced Static Mesh generators

Many of these may update hundreds or even thousands of components while editing.

Personally, I’ve run into this while building procedural construction tools where I’d love to keep the live preview, but rebuilding every tiny mouse movement causes the editor to hitch.

Proposed Solution

Add an optional Construction Script preview refresh limit.

For example:

Construction Script Preview

:check_box_with_check: Run Construction Script on Drag

Maximum Preview Refresh Rate

  • Unlimited (Current Behaviour)

  • 60 Hz

  • 30 Hz

  • 15 Hz

  • 10 Hz

  • 5 Hz

  • Custom (milliseconds)

Additionally:

:check_box_with_check: Skip intermediate updates while a Construction Script is already running.

Instead of queueing every mouse movement, Unreal would simply rebuild using the newest state once the previous execution finishes.

Why this is useful

This keeps one of Blueprint’s biggest strengths:

Live procedural editing.

Instead of forcing creators to choose between:

  • constant hitching, or

  • no live feedback,

they could simply reduce the refresh rate to something like 5–10 updates per second.

For procedural editing, even 100–250 ms between updates still feels responsive while dramatically reducing unnecessary rebuilds.

Backwards Compatibility

This would not change existing projects.

The default would remain:

Unlimited (Current Behaviour)

Developers who don’t need throttling would never notice the feature.

Why not just optimise the Blueprint?

Optimisation should absolutely be the first step, and techniques such as component reuse, Instanced Static Meshes, caching, and partial updates can significantly improve performance.

However, there are legitimate editor tools where rebuilding is inherently expensive because they intentionally generate or modify large procedural structures. Even well-optimised Construction Scripts may still benefit from a configurable preview update rate.

Existing Related Requests

I’ve found requests for:

  • Construction Script behaviour with splines.

  • Variable slider throttling.

  • Construction Script behaviour in Blueprint components.

However, I couldn’t find a request for a general-purpose configurable Construction Script preview refresh rate that applies across all procedural editor workflows.

I think this would be a valuable quality-of-life improvement for Blueprint authors, technical artists, and tool programmers creating increasingly sophisticated editor tooling.