How do I fix this water flowing under water problem?

How do I fix this?

Waterfall:

http://img98.imageshack.us/img98/2027/doom0001ug9.jpg

Waterfall underwater problem:

http://img117.imageshack.us/img117/3777/doom0000copyai9.jpg

Its a pic from my old wad 'Dark7 mission pack' (map04) at the start point where you fall down from the sewer into the deep water. Any way to correct this mistake?

Thanks
Bryant (Gunrock) Robinson

There's several ways you could fix that. Be creative...
If it were me, I'd probably make the waterfall deep water too.

One way to fix it is to have the underwater section as a separate sector(s) and have the player silent-teleport there using the eyes-go-below-fake floor special. That way the underwater sector will not have a waterfall texture, because it is completely separate from the above-water sector with the actual waterfall.

Another way to do it is to have a very thin sector underwater and right below the waterfall. The sector width will be the same as the waterfall width, the floor will have the same height as the fake water floor and will have the water flat, and the lower textures will be the same as the surrounding rock/brick of the rest of the underwater area.

A third way to do it is to have the actual waterfall linedef as a separate line that is not part of any sector (i.e., does not enclose any sector). Assign the waterfall texture to the Main (i.e., Middle) texture of the sidedef, and move the linedef to within 1 unit of the sector behind, which will have a rock/brick lower texture that continues underwater. This is not such a convincing method, as the player can generally tell that the 1-unit gap exists. Moreover, as the Main sidedef texture is being used, it will not tile. Therefore, this method can only be used for waterfall heights that exactly match the height of the waterfall texture.

ReX said:

Moreover, as the Main sidedef texture is being used, it will not tile. Therefore, this method can only be used for waterfall heights that exactly match the height of the waterfall texture.

... which can be changed with a new line flag in ZDoom.