Particles disappear when "Play on PC"

[agentfx]

I made a particle system, When I "play from here" or "play from here in viewport" I see it and everything is as expected. But when I try to "Play on PC" it's not there. Tried saving, rebuilding... can't seem to figure it out. Any help?

EDIT: SOLVED

[Nawrot]

It is because of optimization.

Play with LOD settings of particle system (it is in cascade editor), but this usually helps only when particles are visible but not all rendered (fewer than you put in cascade editor).

I think in your case its this problem:
distance to particle system is calculated from Emitter actor, if its embdeded in geometry or behind occluding mesh sometimes it is optimized out of game. So always place them in well visible spots and then adjust origin of particles by adding "location" node to particle system. And then set lod distances for it to be visible in area you want.

[agentfx]

I wasn't using any LOD so it should render full at any distance. I'm putting an updated version of this effect
http://forums.epicgames.com/showthread.php?t=744564
in the example scene "ExampleMap" which is small, as in 1 room with an lift. There is no geo occluding it, I've placed it in the center of the room. There is location attrs on some of the emitters not all. I've positioned the actor in scene appropriately, and again it works in "play from here"

[agentfx]

so I tried adding a comes-with-udk particle to my scene and that one works, but mine doesn't... ARGH! Just figured it out! I'm an idiot, and no one could have foreseen that... er maybe, well anyway. I was working with that package outside of the UDK folder, b/c when I started this effect I was working like I would in Maya. I would just open that package when I started UDK. In the meantime I've learned a lot more about how the files work together 'n such and didn't yet put 2+2 together.
anyway, thanks to anyone who might have given this some thought.