Unreal Engine Issues

Attribute Reader + Torus Shape Location module cause NaNs in CPU Niagara systems

It appears using the attribute reader with the shape location module set to torus will cause NaNs. The log mentions Sphere Radius among them, which should not be used with the torus mode. ...

Inaccurate motion vectors when using different position binding in renderer

Even though the particles are not moving, and the velocity is zero, the output motion vectors are non-zero. This seems to only happen if using two sources of particle positions.  ...

Getting Emitter.NumParticles on Niagara's GPU compute sim returns 0

This problem looks like the following parameters are not defined correctly. The correct parameter is Engine_Emitter_NumParticles. Engine_Emitter_NumParticles and PREV_Engine_Emitter_NumParticles .\ ...

NiagaraComponent attached to the character won't stay active when travelling to a new level using seamless travel

The pawn character is added to APlayerController::GetSeamlessTravelActorList, so it'll be persisted during server travel. The Niagara component is spawned during BeginPlay and activated manually. W ...

Preview rendering does not update when slider is moved below 0.0 in timeline on in Niagara Editor.

Workaround in UE5.3:  UNiagaraComponent::TickComponent             if (AgeDiff < 0.0f)             {                 SystemInstanceController->Reset(FNiagaraSystemInstance::EResetMode::ResetAl ...

When creating a new NiagaraSystem using existing system, the DefaultEffectType set in ProjectSettings is not reflected.

When creating a new NiagaraSystem, the DefaultEffectType set in ProjectSettings should be reflected. If another EffectType is already set, it should be respected. The problem here is that when creat ...

Niagara and Water Source Body Component

This has changed from 4.27 and the Deep Dive video on water: [Link Removed] ...

Blueprint instance with NiagaraComponent cannot keep its user parameters, it will restore to the default values after reopening the level

Scratch Pad outputting Audio Spectrum triggers a crash

This is a regression. Tested in //UE5/Release-5.1 CL23901901 The editor crashes after playing in editor when the level contains a niagara system with a scratch pad outputing audio spectrum. ...

When transferring data from CPU to GPU particles using Array, if CollisionQuery is used simultaneously, the Array cannot be read correctly.