Velocity and EmitterTime from particle collision report random values

If you add a particle emitter, and add an
Event Generator

  • Collision
    and
    Actor Collision

Binding an event to that Particle Emitter “OnParticleCollide” will report very random values for Emitter Time, somtimes rising values with each collision, and sometimes falling values.

Velocity will report 0,0,0 always, until the max number of collisions has been reached.

Let me know if this needs a repro project, and i’ll set it up for you.

Hi Jonas_Molgaard,

I’m having trouble reproducing this issue on my end. Are you able to provide some more specific repro steps or a repro project so that we can look in to this issue?

Here you go. It prints out the velocity on collisions. You will see zero’s for the first 4 events and then something for the final collision. Try also add debug print for the Duration, and you will see strange values

Also observe that sometimes the casing fall through the ground.

Hi,

Thanks for providing that project, I can see what you mean and I have logged JIRA UE-51529.

Our developers will be investigating the issue further. Please follow that link to monitor the status of the report.

Hi @Jon X, i followed your link, and noticed that it’s marked as “Won’t fix”, which i can sort of accept, but is there any chance of an explanation for this? And what workarounds to use instead then?

With the recent release of engine version 4.18 our developers are focused on high priority crashes and blockers. Regarding a workaround, I will continue to investigate and post here if I find anything useful.

Hi, sorry to bring back this thread, but is there a documented workaround? And here it is backlogged more recently: