User parameters & data interfaces
Agree the input data, units, ranges and update behaviour.
Unreal Engine · Niagara VFX
Design the runtime contract for one reusable system: what drives it, what designers can change and how it scales with the scene.
Example starting scope
Agree the input data, units, ranges and update behaviour.
Separate emission, appearance and behaviour so presets share the same system.
Define distance, density and quality controls for the target platform.
Relevant work
JDM’s documented surface-reactive particle system is the relevant production example. Public material shows the gravel effect; implementation access and profiling are scoped separately.

What we check
Review idle, acceleration, surface changes and missing or out-of-range input.
Check two agreed presets and representative simultaneous instances in the project.
Related scopes and guides
Yes. Existing systems can be debugged, reorganized, extended or optimized without rebuilding the entire effect family.
Yes. Runtime data and exposed parameters are often central to making an effect useful in production.
Your project
Send the Unreal version, current system or reference, runtime inputs and the target scene or platform.