Mapping:What is a brush

A brush is a convex Volume.

This Volume is always bounded by four or more Planes, each Plane forming one Face of the Brush.

Each Brush Face has a set of Texture, Surface and Content properties.

Texture properties are a small number of values defining: ONE Shader Name, XYZ Scale/Stretch values, rotation.

These values are stored along with each face in the mapname.map file.

One Brush Face can only have one set of Texture properties.

Surface and Content properties are stored in an external Shader script. However, some Content properties may still be stored along with the Texture properties in the mapname.map file, one example being detail.