Hello experts. I am an indie dev working in Unreal Engine for Fortnite (a watered down version of UE). Due to certain limitations in side UEFN, I am trying modify a Laser Beam VFX’s end position without using blueprints, basically trying to do it all inside the Niagara System. My approach has been to use the basic setup which uses a User Exposed position parameter, and modify that parameter based on the collision location of a another emitter. My issue is that I cant set a User Exposed parameter, and so I have been trying to find a parameter that I can write to from one emitter, and then also read that parameter from a different emitter. It sounds like a possible thing to achieve but I am pretty amateur at Niagara FX. Any help or guidance would be greatly appreciated, and I can always try to clarify if needed. Thank you 
Hey there Strawhatani! Alright can you please clarify what you’re trying to do because it’s def
possible! It’s just I may be thinking of something entirely different to what you’re going for.
Absolutely and thanks for trying to help. So in the picture below you can see that my beam emitter has a Beam End set to a User Parameter EndPosition. My goal is to update that parameter within niagara, and the way I want to update it is based on a collision event generated by another emitter in that same system. My issue is that I do not know how to write to a parameter based on a collision events collided position, and I dont know what parameter I would use to be able to write to from one emitter and read from it for the one that I use to set my beam end position. Edit I am aware of using the event handler and receive collision event module, but do not know what steps to take from there.
More screenshots attached below.
Alright we’ve narrowed it down nicely but one more question I have is what are you creating? Is it like sparks that appear at the end of the beam,
or say a particle that shoots out then collides somewhere which is why you need the collider information?
Or is it a laser which you want to always collide to the nearest surface?
We’re close to solving it, just the final push!
Yea im just trying to create a simple laser that will have an end position set to whatever surface it collides to first. The collider emitter is basically just detecting the collision location and Im trying to set that location as the beam end position.