Door_Open

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11:Door_Open (tag, speed, lighttag)

tag: Tag of affected sector 
speed: How quickly the door opens 
lighttag: Tag of sector to perform a gradual lighting effect in

Raises the ceiling of all affected sectors to four units below the lowest surrounding ceiling. If tag is 0, then the sector on the line's back side is used.

If lighttag is non-zero a gradual lighting effect is done in the tagged sectors. The light is gradually changed between the darkest neighboring sector when the door is fully closed and the brightest neighboring sector when the door is fully open.