Linedef type 121, Water, Translucent, is a type of translucent water block. The block is intangible, and players hear and see a "splashing" effect when moving in and out of it. While inside the block, the scene becomes distorted, and the field of view warps into wavy lines. Also, while inside the block, players will move more slowly, and their gravity is lowered slightly. If a player remains in a water block too long without grabbing air bubbles or acquiring an Elemental Shield, a countdown will be initiated after 20 seconds, just like in the original Sonic games. If the time runs out, the player automatically drowns. Water blocks can also be used to create slime and lava, if they have the right sector effects applied to them.
Setup
The flats, floor height, and ceiling height of the FOF are determined by the flats, 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.
The alpha value of the FOF's translucency can be changed by setting the control linedef's front side upper texture to the number symbol (#), followed by a three-digit decimal number, from 000 to 255. #000 is completely invisible, whereas #255 is completely opaque. Note that in the Software renderer, there are actually only eleven different values: #000–#011, #012–#037, #038–#063, #064–#088, #089–#114, #115–#139, #140–#165, #166–#191, #192–#216, #217–#242, #243–#255, where #000–#011 is invisible, and #243–#255 is opaque. The advantage of using the completely opaque values is the ability to properly render flats which use transparent pixels. If no value is set in the front side upper texture, however, the default alpha value of #128 will be used.
If Flag [6] / Not Climbable is checked, the FOF will always render a separate light level, which means that the light level of the control sector will only affect the water block instead of affecting the block and below it. If Flag [9] / Solid Midtexture / Effect 4 is checked, the water block will use the light level of the target sector instead of the light level of the control sector. If Flag [10] / Repeat Midtexture / Effect 5 is checked, the flats will use the "ripple" effect.
Linedef special info
Floor height
Height of bottom of FOF
Ceiling height
Height of top of FOF
Front upper texture
Alpha value of FOF's translucency, from #000 to #255 (#000 is completely invisible, #255 is completely opaque, #128 is default)
Linedef flags
[6] Not Climbable: Always renders a separate light level [9] Solid Midtexture / Effect 4: Uses light level of target sector instead of the control sector Repeat Midtexture: Flats use the "ripple" effect
9F39 – Without flags 29F39 – Not Climbable 80009F39 – Solid Midtexture 40009F39 – Repeat Midtexture 80029F39 – Not Climbable + Solid Midtexture 40029F39 – Not Climbable + Repeat Midtexture C0009F39 – Solid Midtexture + Repeat Midtexture C0029F39 – Not Climbable + Solid Midtexture + Repeat Midtexture
Aesthetic tips
Water blocks are generally put in a pit, to simulate real water. But since water blocks are set up like any other FOF, they can be made to float in the air, or rest on top of a flat surface without a pit. However, this is not recommended, as it looks unrealistic.
While water blocks can be used alone, it is common (and generally recommended) to apply a hue to it. This is done by creating another control sector using a colormap (or by applying it to another linedef on the water block's control sector) and tagging the water block's control sector to create the hue within the water block.
