Focused reference · Unreal Engine 5.8

Presets, Patches, and interfaces

unreal-metasounds/references/presets-patches-and-interfaces.md

Patch

Extract a Patch when the same bounded DSP/control behavior is reused: randomized wave choice, envelope mapping, surface selection, filter chain, or musical utility. Document every pin, unit, default, and timing assumption. Changes propagate to containing graphs; test representative callers.

Preset

Right-click a Source/Patch -> Create MetaSound Preset. A Preset inherits a read-only graph and overrides selected default Inputs. Parent changes propagate. Use Presets for variants sharing the same behavior contract; convert from Preset only when the graph must diverge. Constructor-pin status cannot be overridden on Presets.

Interfaces

Interfaces supply standardized Inputs/Outputs connecting MetaSounds to audio-engine systems:

UE.Source.OneShot: On Finished for finite source lifetime.
UE.Attenuation: listener distance input.
UE.Spatialization: azimuth/elevation inputs.

Add/remove interfaces in the MetaSound Interfaces panel. Do not retain OneShot on indefinite sources. Treat interface changes like an API migration because dependent graphs/callers may rely on members.

Use templates only when repeated asset construction and curated designer controls justify the extra framework. For a small graph, a normal Source/Patch/Preset is clearer.