unreal-performance

Performance and Optimization - Unreal Engine 5.7

Tick and Updates

• ALWAYS disable Tick if not necessary: PrimaryActorTick.bCanEverTick = false;
• Use FTimerHandle for periodic updates instead of Tick
• Use events and delegates instead of polling
• Consider SetActorTickInterval() to reduce Tick frequency

Garbage Collection

• Minimize UObject allocations during gameplay
• Use object pooling for frequently created/destroyed objects
• Avoid creating UObjects in loops
• Use structs instead of UObjects when possible

Containers

• Use TArray with Reserve() when size is known
• Use TMap for O(1) lookups, TArray for iterations
• Avoid TArray::Find() in loops - use TMap or TSet
• Use TArray::RemoveAll() instead of loops with Remove()

Strings

• Use FName for frequent comparisons (case-insensitive, hashed)
• Use FString only when necessary (mutable, slow)
• Use FText for UI (localizable)
• Avoid string concatenation in loops

Math

• Use FVector, FRotator, FTransform (optimized)
• Use FMath for math functions
• Avoid unnecessary conversions
• Use Squared versions when possible (ex: FVector::DistSquared())

Logging

• Use UE_LOG() with appropriate levels
• Disable logs in Shipping builds
• Avoid logs in loops or frequently called functions
• Use UE_LOG with LogTemp for temporary debug

Networking

• Use Replicated only for properties that need to synchronize
• Minimize replicated data
• Use ReplicatedUsing for callbacks when values change
• Consider NetMulticast vs Server vs Client RPCs

Profiling

• Use Unreal Insights for profiling
• Use SCOPE_CYCLE_COUNTER() to measure performance
• Use STAT() macros for statistics
• Profile before optimizing - measure, don't guess

General Best Practices

• Prefer stack allocation instead of heap when possible
• Use const and constexpr when appropriate
• Avoid virtual functions in performance-critical code
• Use inline for small and frequent functions
• Cache results of expensive calculations