Hello !
Simple question : How i can remove particle in an area ?
Imagine i’ve got a box of 10x10x10, i want particle outside of this box to be visible, and inside, unvisible (can be destroyed too, doesn’t really care).
How i can proceed ? can we have a trick with material ?
Kill particles in volume module:
Depending on how your system in setup, you may have to increase the spawn rate, as this solution is destroying them as they cross into the volume.
A more elegant solution would be to script a module that just sets them as not visible during their time in the volume.
Thanks for your answer @ClockworkOcean,
The issue is depending of the level, i will have multiple volume (buildings) where i want those area. There is no other solutions than this ?
I was really thinking about some trick with materials en particle materials.
Is this like rain or snow? Then it’s much more efficient to make a block of particles that follows the player/camera. There’s a trick to making them not look like right
Rain, don’t bother. But if it’s a slow moving particle, then you need this.
Well, i should admit you solve with this video one of my issue =D
It’s snow particle.
The fact is i’ve got a lot of inside (buildings) and outside (landscape). I want to avoid snow inside building. The issue is to remove the snow inside the buildings.
I think with the trick in the video, i’m maybe be able to make the snow fall, and use Distance Field Mesh Collision working. The issue i was facing is as DFM collisions is traced visibly against global distance field, at distance it’s not working properly. But as this trick allow to have a very small box around the player, it maybe gonna work better.
Thanks a lot, i will try this and keep you updated if it working !
Definitely better to have a box around the player, than particles in the whole level 
When the player goes indoors, you can remove the box, or move it outside the window.
Yeah, i was not using a whole particle in the whole level (it’s a 2km area) but a moving snow.
But i wasing using the trick to respawn particle who is outside the box (and this is a pretty smart trick who solve a lot of generation issue ! Thanks for this).
Yeah, i think will maybe try a avoidance volume who is in charge to keep the particle box outside the nearest window. Should do the trick.
There’s a lot you can do if you can be bothered to hack ( copy and hack ) the module code in Niagara. For instance, you could have tagged actor volumes around the level, and in the particle update module, just kill the particle if it’s in one of them…
