DannyCT posted a topic in EffectsHi there, First time post here. I'm relative new to Houdini and I really love already it but there are some things that (probably) are really simple but I just can't figure out. I must admit that I have very little experience in expressions and python (which I'm already working on) but for something I'm currently working on I'd hope to have some help before I get proficient enough in that. I have a volume source which emits in the Y axis and I wanna use the gas disturb fields but only on the voxels that are being emitted for the first second, after that I want other microsolvers that I have in the scene to take over. What kind of expression should I use for that? Should I first add some kind of life-attribute and then refer to that or is it much simpler? I looked at the local variables in the gas disturb microsolver but as far as I can tell they all refer to the simulation step time which is in the beginning of the whole simulation. Some help ore pointers are really appreciated. Thanks!