Mode Toolbar

(A) : Sets and displays the active Brush Mode. Active mode is indicated by a blue accent line below it's icon.

Choosing any of Unity's standard tools (Pan, Move, Rotate, Scale) will automatically de-activate Polybrush.

Brush Settings

(B) : Brush Settings lets you choose Radius, Falloff, Strength/Opacity, and Falloff Curve.

You may also save and load often used brushes via the Brush Preset selector.

Brush Mirroring

(C) : Chooses the Brush Mirroring methods to use with the current brush.

Mode Settings

(D) : Any additional settings specific to the current Brush Mode.