Light_ForceLightning
From ZDoom Wiki
109:Light_ForceLightning(mode)
mode: Decides which operation to perform (development version only)
- 0: Makes lightning flash immediately and keeps the map in lightning mode as if it had been set in MAPINFO.
- 1: Makes lightning flash only once and terminates lightning mode right away.
- 2: Terminates lightning mode now. (Won't interrupt a current lightning flash, however)

