Brush

Brush is a simpliest geometry unit in a level. Other geometry units are misc_model and patches.

Brush is consecutive solid geometry. It defines a form made of it's sides and a volume which is anyting inside. Brush is using this rules:

• Minimum 3 sides
• Each side is polyhedron (maximum 16-24 corners)
• If slice brush by the plane of any of it's sides, all brush will be on one side of the plane

Since brushes define volume, they are used for water, lava and slime.