A player falls through an intangible FOF with only it's sides rendered.
Linedef type 222, Intangible, Sides Only, is a type of floor over floor block which can be passed through, and does not render floor and ceiling flats. It is generally used if the top and bottom will not be viewed anyway, as a means of reducing the amount of CPU processing power used to render the level. It can also be used to add middle textures to the edge of FOFs, instead of offsetting the texture from the sector floor to the FOF or checking Flag [4] / Lower Unpegged. The upside to this method is that the middle textures can be made to move with moving platforms simply by making the intangible FOF also a moving platform. However, it can also sometimes result in the tutti-frutti effect, so this method should be used with caution.
Setup
The floor height and ceiling height of the FOF are determined by the floor height and ceiling height of the control sector, and the sidedefs of the FOF's walls are determined by the sidedef of the control linedef.
If Flag [6] / Not Climbable is checked on the control linedef, the FOF will cast a shadow. In this situation, the light level of the control sector will determine the brightness of the shadow cast by the FOF. If the light level of the control sector is lower than that of the target sector, then it will cast a dark shadow. If the light level of the control sector is higher than that of the target sector, then the FOF will illuminate the area below it. If the light level of the control sector is equal to that of the target sector, then the FOF will not affect the light of the area below it.
Linedef special info
Floor height
Height of bottom of FOF
Ceiling height
Height of top of FOF
Sector light level
Brightness of shadow cast (If [6] Not Climbable is checked)
