How to add lava, water, glass and other materials to your map
To add lava, water, glass, and other materials to you map you first have to make a cube in edit mode like this (Picture avalible soon!). After this you open the quickedit window, (F3) and go to the materials tab, then pick which material you wish to make this cube of. Click this material, exit edit mode and you have your very own block of lava, water, or glass.
Effects of each material
Air: Creates a block of empty space! (Can be used to remove other materials.)
Clip: Creates an invisible wall.
Glass: Creates a window effect.
Lava: Creates a burning wall of lava! (It will kill you if you walk into it.)
Noclip: Alows you to remove the effects of clip.
Water: Creates a swimming area! (What fun.)
Respawn: Unknown Effects. (Sorry.)
Hope this helps,
Nightmare2U