Creating a brush entity

Brush entities are built from brushes and utilize their geometrical volume or physical features (i.e. for an area to effect or for a button). They include things such as triggers, conveyor belts, and rain.

How to create a Brush Entity

1. Create a new world brush.
2. Select it in one of the 2D views.
3. From the right-click menu, choose Tie to Entity, or click the To Entity button in the bottom right corner. (Or press Ctrl+T)
4. Select the type of brush entity to create from the Class list.
5. Click Apply.

The standard for every brush entity is defined in the actual game's settings, but it is usually func_detail, which is solid for everything.

For a list of current HL2 Brush Entities see the Category: Brush Entities