The brush tool can be used to either draw displacements (sculpting), or colors (vertex color) on a polygon mesh.

A displacement painted with the push/pull brush.

Modes
The brush tool is available in point, edge, polygon and object mode and can only be applied on raw polygon objects.

• 
  To use the Brush tool you first have to select an editable polygon object and then pick the Brush tool via the "Tools->Polygon->Brush" menu item. Now you can start painting on the mesh.

Properties

• Type: The brush type.
  • Emboss: The emboss brush moves the vertices within the brush radius along the vertex normal.
  • Move: The move brush works like a magnet and pulls the vertices within the brush radius into the direction of the mouse cursor.
  • Pull/Push: The pull/push brush can be used to paint displacements on a mesh. Hereby the vertices are moved along the vertex normal.
  • Smooth: The smooth brush smoothes out uneven meshes.
  • Color: The color brush paints vertex colors on a mesh. It automatically creates a vertex color tag if it doesn't already exists.
• Color: The color which is used for painting vertex colors.
• Strength: The strength of the brush.
• Radius: The radius of the brush (in screen space pixels).
• Focus: The inner radius of the brush (relative to the outer radius). Vertices within that radius are weighted with 100%.
• Additive: When checked, the brush weights are slowly accumulated.
• Falloff: The falloff curve of the brush. This profile is applied to vertices which are within the brush radius but outside the inner (focus) brush radius.
  
  The Falloff editor has a context menu with
  some predefined profiles.