Brush Contents

A brush can say what it is made of: Solid, Glass, Water, or a type you add to the project's contents list. Normally the CSG deletes the faces where two brushes touch, because they are inside the level. Where brushes of different contents meet, the faces stay: the metal frame behind a glass pane keeps its face, and so does a wall standing in water.

• Generators show a Contents setting.
• Water and lava volumes can sit against, or around, solid geometry, while tunnels still carve through them.