Mouse click to world: detect clicked actor or ground position

On Left Mouse Button pressed → GetHitResultUnderCursorByChannel(TraceChannel=Visibility) → Branch(ReturnValue=true) → BreakHitResult → Check HitActor: IsValid(HitActor) → Branch → True: interact with HitActor. Check ground: use ImpactPoint as the world position clicked. GetHitResultUnderCursorByChannel is on PlayerController. Inputs: 'TraceChannel' (ETraceTypeQuery) and 'bTraceComplex' (bool). Output: 'HitResult' (struct) and 'ReturnValue' (bool). Use BreakHitResult to get ImpactPoint, HitActor, etc.

Procedural mesh placement on terrain using line trace downward

Pattern for snapping object to ground: GetActorLocation → Add Vector(Z=+1000) → as TraceStart. GetActorLocation → Subtract Vector(Z=1000) → as TraceEnd. LineTraceByChannel(Start=TraceStart, End=TraceEnd, TraceChannel=Visibility) → Branch(ReturnValue=true) → BreakHitResult → SetActorLocation(NewLocation=ImpactPoint) → SetActorRotation(NewRotation=MakeRotFromZ(Normal)) [align to surface normal]. MakeRotFromZ takes a 'Z' input Vector and outputs Rotator aligned to that normal.

SpawnEmitterAtLocation — spawn particle effect at world location

UGameplayStatics::SpawnEmitterAtLocation. For Niagara, use SpawnSystemAtLocation.

Spawn actor at location with collision handling

Pattern: Trigger → SpawnActorFromClass(Class, MakeTransform(Location, Rotation, Scale), CollisionHandling, Owner) → ReturnValue → IsValid branch → use spawned actor. Always check IsValid on ReturnValue. For many spawns, spread across frames with timer to avoid hitches.

Create a Blueprint for a health pickup that restores health when overlapped by the player

SpawnEmitterAtLocation — spawn a legacy Cascade particle system

Legacy Cascade system. Prefer Niagara (SpawnSystemAtLocation) for new projects.

GetCurrentLevelName — get the name of the currently loaded level

AddImpulse — apply instant impulse to physics body

One-shot force. bVelChange=true treats Impulse as velocity change.

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Spawn actor at location with rotation

Pattern: MakeTransform(Location=SpawnLocation, Rotation=SpawnRotation, Scale=(1,1,1)) → SpawnActorFromClass(Class=ActorClass, SpawnTransform=Transform) → CastTo<YourClass>(ReturnValue). SpawnActorFromClass inputs: 'ActorClass', 'SpawnTransform' (Transform), not separate Location/Rotation. Use MakeTransform node to build the Transform struct from Location+Rotation+Scale.