Lighting effects

Most lighting effects in the Doom engine are set as a sector types, but it is also possible for Linedef types to change a sector's lighting.

1: Light flash
The sector's light randomly flashes between its brightness and the darkest neighboring sector's brightness. If all neighboring sectors have the same or higher brightness than the flashing sector, the sector's light will not flash.

2: Strobe flash, slow
The sector's light is the brightness of the darkest neighboring sector and it will flash at its defined brightness every 35 tics. If all neighboring sectors have the same or higher brightness than the flashing sector, a brightness of 0 is used for the "flash".

3: Strobe flash, fast
The same as sector type 2, but it flashes every 15 tics.

4: Strobe flash, fast, super hellslime damage
The same as sector type 3, but it also causes 20 damage to the player every 32 tics.

8: Glow
The sector will glow between its brightness and the darkest neighboring sector's brightness. If all neighboring sectors have the same or higher brightness than the glowing sector, the sector's light will not glow.

In software rendering engines, this gives the sector's light the appearance of brightening towards the player and then darkening away from them, the speed of this effect becomes more pronounced the greater the difference between the brightness levels. Hardware rendering engines may not handle this effect differently.

12: Strobe flash, slow, in sync
This is the same as sector type 2, but all sectors assigned this type will flash at the same time. This is useful when a level designer wants to have a lighting effect continue into multiple sectors.

13: Strobe flash, fast, in sync
Like the above, this is the same as sector type 3, but all sectors assigned it will flash at the same time.

17: Fire flicker
The sector's lighting will be 16 brighter than its assigned value, and it will flicker to its assigned brightness randomly.

Linedef types
TODO