Entities: func_wall

This entity is a brush entity. This means that its size and shape are defined by the solid(s) that constitute it in Hammer.

This entity is used to construct basic level geometry. The game uses all faces on one plane to perform collision detection. The remaining faces are ignored by the game and not rendered or collided. You can allow or deny portal creation on its surfaces.
Properties:

• Axis Choice (axis_choice) - Defines which axis aligned plane to use as the significant surface. All faces on that plane will be considered in-game and all others ignored
• Wall Type (wall_type) - Defines whether or not portals can be placed on the wall. 'Wally' allows them while 'Metal' does not