My full FLEP settings for
vertical dust ceiling-to-floor like in
this video.
I used smoke emitter white and a custom sprite (nr. 20 [optional], change it with wadmerger)
Sprite download
Emitter start color: 0,0,0
Emitter start time: 50
Emitter end color: 41,36,20 (optional)
Emitter end time: 128
Emitter blending mode: 2 or 8
Emitter lifetime: 500
Emitter size var. lower type: 128
Emitter size var. higher type: 0
Emitter size multiplier: 4
Emitter rotation: 0
Emitter flags: 1000001000011010
Emitter hor. speed: 0
Emitter hor. curve: 2
Emitter vertical speed: 5
Emitter vertical speed: 10
Emitter spawn interval: 105
Emitter sprite: 20 (optional)