UKismetMathLibrary::MakeRandomStream
#include "Kismet/KismetMathLibrary.h"
Access: public
Specifiers: staticBlueprintPureUFUNCTION
Description
Creates an FRandomStream initialized with a specific seed. The stream is fully deterministic — the same seed always produces the same sequence of random numbers, making it suitable for reproducible procedural generation.
Caveats & Gotchas
- • Two FRandomStream instances with the same seed run in perfect lockstep and produce identical sequences. If you need independent random behaviour in multiple systems, use different seeds derived from distinct sources (e.g. ActorID ^ FrameNumber).
- • Seed 0 is valid but generates a fixed predictable sequence that feels non-random to players. Avoid using it as a default; prefer initializing with a value like FMath::Rand() at startup when reproducibility is not required.
Signature
static ENGINE_API FRandomStream MakeRandomStream(int32 InitialSeed);Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| InitialSeed | int32 | The seed value that determines the random sequence produced by this stream. | — |
Return Type
FRandomStream Example
Create a seeded stream for reproducible level generation C++
int32 LevelSeed = 42;
FRandomStream Stream = UKismetMathLibrary::MakeRandomStream(LevelSeed);
float SpawnChance = Stream.FRand(); // always same value for seed 42Version History
Introduced in: 4.0
| Version | Status | Notes |
|---|---|---|
| 5.6 | stable | — |
Feedback
Was this helpful?