Linedef type 120, Water, Opaque, is the most basic type of 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.
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 the area 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 water block's flats will use the "ripple" effect.
Linedef special info
Floor height
Height of bottom of FOF
Ceiling height
Height of top of FOF
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 [10] Repeat Midtexture / Effect 5: Flats use the "ripple" effect
8F39 – Without flags 28F39 – Not Climbable 80008F39 – Solid Midtexture 40008F39 – Repeat Midtexture 80028F39 – Not Climbable + Solid Midtexture 40028F39 – Not Climbable + Repeat Midtexture C0008F39 – Solid Midtexture + Repeat Midtexture C0028F39 – 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.
It is generally a very bad idea to place an opaque water block above a death pit, as the player will not realize the danger until it is too late to avoid it. If you want to place water in a death pit, it is strongly recommended that you use linedef type 121 or linedef type 123 instead, as the player will then be able to see the death pit through the water.
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.