Brush

Reference

Mode:Sculpt Mode
Panel:Toolbar ‣ Tools ‣ Brush
Menu:Brush ‣ Sculpt Tool
Brush Type
TODO.
Radius
This option controls the radius of the brush, measured in pixels. F allows you to change the brush size interactively by dragging the mouse and then LMB (the texture of the brush should be visible inside the circle). Typing a number then enter while using F allows you to enter the size numerically. Brush size can be affected by enabling the pressure sensitivity icon, if you are using a Graphics Tablet.
Strength

Controls how much each application of the brush affects the model. For example, higher values cause the Draw brush to add depth to the model more quickly, and cause the Smooth brush to smooth the model more quickly. This setting is not available for Grab, Snake Hook, or Rotate.

You can change the brush strength interactively by pressing Shift-F in the 3D View and then moving the brush and then LMB. You can enter the size numerically also while in Shift-F sizing. Brush strength can be affected by enabling the pressure sensitivity icon, if a supported tablet is being used.

ちなみに

If the range of strengths does not seem to fit the model (for example, if even the lowest strength setting still makes too large of a change on the model) then you can scale the model (in Edit Mode, not Object Mode). Larger sizes will make the brush's effect smaller, and vice versa.

Direction Ctrl
Brush direction toggle, Add raises geometry towards the brush, Subtract lowers geometry away from the brush. This setting can be toggled with Ctrl while sculpting.
Autosmooth
Sets the amount of smoothing to be applied to each stroke.
Topology
See Dyntopo.
Normal Weight Ctrl

Constrains brush movement along the surface normal. Especially useful with the Grab brush, can be temporarily enabled by holding Ctrl. E.g. Grab brush can be used to push a depression (hole) into the mesh when Normal Weight is set.

Applies to Grab and Snake Hook brushes.

Plane Offset
Offset for planar brushes (Clay, Fill, Flatten, Scrape), shifts the plane that is found by averaging the faces above or below.
Plane Trim
Ability to limit the distance that planar brushes act. If trim is enabled vertices that are further away from the offset plane than the trim distance are ignored during sculpting.

Options

Accumulate
Causes stroke dabs to accumulate on top of each other.
Radius Unit
TODO.
Sculpt Plane

Use this menu to set the plane in which the sculpting takes place. In other words, the primary direction that the vertices will move.

Area Plane
The movement takes place in the direction of average normal for all active vertices within the brush area. Essentially, this means that the direction is dependent on the surface beneath the brush.
View Plane
Sculpting in the plane of the current 3D View.
X, Y, Z Plane
The movement takes place in the positive direction of one of the global axes.
Original Normal
When locked it keeps using the normal of the surface where stroke was initiated, instead of the surface normal currently under the cursor.
Front Faces Only
When enabled, the brush only affects vertices that are facing the viewer.
2D Falloff
This turns the brush influence into a cylinder (the depth along the view is ignored) instead of a sphere. It can be used along the outline of a mesh to adjust its silhouette.