I am trying to make a muzzle flash particle system for a scifi cannon. For that I wanted a beam with particles sort of hanging around the beam, basically built off three template emitters:
My problem really pertains to the HangingParticulate though, specifically the “Shape Location” block:
I am setting the Beam End and Cone Axis params from a blueprint and I know they are properly written because the DynamicBeam and DirectionalBurst emitters properly follow those parameters.
However, the HangingParticulate emitter seems to behave oddly in-game at certain source rotations.
I was able to use Blueprint debugging to find out that whenever my direction vector / rotation axis (this is basically my Actor Forward Vector from BP) has components with negative values, those seem to be Abs()'d and thus inverted inside Niagara; I am passing a vector with negative values in when this problem happens. This seems to be contained to the “Shape Location” call exclusively. I’ve pretty much tried all possible combinations of settings in the Rotation part, but none would actually help.
This is on UE 5.1.1.
What am I doing wrong here? Is there a different approach to achieve a similar effect?