Level particle effects don't display the first time a level is streamed in

I’m having a strange issue where all particle effects in a particular sub level do not show the first time the level is set to be visible. If I stream the level out and back in all the effects are working fine!

I’ve turned on verbose logging for LogParticles and they get activated fine during the first stream in I just can’t see them.

I’ve tried many different things to no avail. Was wondering if anyone has run into this before?


Hi Sid,

How are you loading the streaming level? I did a quick repro in 4.11 and don’t see the issue you are describing. Do you have any more details to share that may help me re-produce your issue?

Hi Tom!

Thanks for responding! I’ve been trying to drill down to figure out the circumstance and have come up with the following.

We are streaming just using streaming volumes. Currently the levels are all set to Always Loaded where the volumes just toggle visibility, however, I have also tried the same test using blueprint streaming method. The level is broken up into several sub-levels, we’ll say level A, B, C, D, etc. We have a blueprinted torch with a sconce mesh and two emitters, one fire, and one smoke. This blueprint is placed all over the level, in pretty much every sub level. The same fire emitter is also placed as simple Emitter actors.

So starting the level A and B are loaded. All fire is fine. Moving through the level C streams in, and A stream out, fire is still good. You get to a point in the level where only C is loaded, then D loads in. When i get to the level we have no fire! Same torches / emitters. C is still blazing glory. I move to unload D, then move back to load D and fire is fine.

I have been able to simplify further where I can start from the point where D is about to load (without traversing the whole level) and I can reproduce the same thing. So I feel like it’s something specific with the level itself.

I feel like this is something simple I’m missing. I’ll keep digging and let you know if I find anything else. If you have any other ideas of where to look let me know!

Thanks again!

Ok Sid! Let me know if you have any more questions.