The Brush > Auto Masking sub-palette controls the auto-masking features.
Mask By Polygroups
The Mask By Polygroups will apply a virtual masking based upon the polygroups of the tool. If you have the setting at 100 then the first selected polygroup will be the only part of the mesh that can be edited by selected brush. If you have the slider any lower then that will allow multiple polygroups to be edited on a given stroke but with less intensity then the first selected polygroup.
Auto Mask Mesh Insert
When Auto Mask Mesh Insert is turned on the base mesh will automatically be masked for all InsertMesh and InsertMultiMesh brushes.
Auto Mask FiberMesh
The Auto Mask FiberMesh button allows your brush to control a specific segment of each fiber that will be affected by the brush as you sculpt or paint. Use the FiberMesh Mask Curve to control how the mask is applied.
FiberMesh Mask Curve
The FiberMesh Mask Curve allows you to control how the Auto Mask will be applied to the individual fibers.
Bottom to top in the curve represents Mask Intensity, left to right is the span of the fiber from root (on the left) to tip (on the right).
This curve gives a very high degree of control when using the Groom Brushes to style and arrange fibers.
Directional
The Directional button will apply a virtual masking based on the the direction of a stroke.
This is an extremely beneficial when Dots with a Roll in the Stroke Palette is turned on. The alpha will follow the direction of the stroke at all times. Changing the Focal Shift in the Directional Mask Curve will give control of the alpha placement with minimal overlapping of the alpha. Moving the ClayTubes brush to a Focal Shift of about 95 with Roll and Dots on is a great example.
ByPressure
The By Pressure slider controls the Directional Masking by pen pressure. If the slider is set to 0 then the pen pressure will have no affect to the Directional Masking. If the By Pressure slider is set to 100 then when 100% pen pressure is applied the Directional Masking will be disabled.
DirectionalMask Curve
The Directional Mask Curve will control the alpha’s overlap.
CavityMask
Cavity Masking is one of three real-time masking features. Cavity Masking will mask surface relief leaving you free to paint or sculpt on the surface of the model without effecting those areas that are cut into the model. You can invert the effect by setting Cavity Masking Intensity slider to a negative value.
Cavity Masking allows you to simulate dry-brush effects while Poly Painting. It is also useful when sculpting wrinkles on pore level detail on your model. Adjust the intensity of Cavity Masking with the slider to the right of it. Adjust the behavior with the Cavity Masking Curve.
CavityMaskInt
Determines the strength of the automatic masking effect. High values mean that even relatively flat recesses will be masked; lower values cause only more significant cavities to be masked. Negative values cause raised areas to be masked.
CavityMaskCurve
When Brush:CavityMask is on, this curve can be used to affect how strongly automasking is applied to areas that are more or less recessed. You can even use it to reverse the effect of the auto cavity masking, so that cavities are not masked and non-cavity areas are masked.
Note that this is an AUTOMATIC effect; the mask will not be shown, and it will change dynamically as the shape of the model changes.
BackfaceMask
Press Backface Masking when working with thin-edged models. Backface Masking masks areas that are facing away from your sculpting. This will preserve details and form in areas usually not visible to you while sculpting.
When Backface Masking is on, then areas of the model facing away from the user will not be affected by sculpting. This can be very useful when, for example, trying to sculpt one surface of a thin model such as a piece of leather. Without BackfaceMask on, any brush radius greater than the thickness of the leather would also affect the opposite side of the leather model. Use the Intensity slider to adjust the effect. The Backface Masking Curve gives you even more control over the effect. Note that this is an AUTOMATIC effect; the mask will not be shown, and it will change dynamically as the shape of the model changes.
BackMaskInt
When BackfaceMask is on, this slider determines the maximum amount of masking that will be applied to auto-masked areas of the model.
BackMaskCurve
Backface masking operates by automasking vertices depending on the angle they make away from the user. The default BackMaskCurve works well for the standard case where the goal is to ensure that sculpting does not ‘leak through’ to the other side of a thin model. However, by changing the curve, you can affect how strongly masking is applied to vertices, as a function of how much the vertices’ normals point away from the user. For example, flattening sections of this curve allows you to produce stairsteps in your sculpting, as ranges of angles will then be masked by the same amount.
ColorMask
Press Color Mask to use the model’s Poly Painting as a mask while sculpting or painting.
This is very useful for creating realistic skin textures and many other things. Note that this is an AUTOMATIC effect; the mask will not be shown, and it will change dynamically as the color of the model changes.
ColorMaskInt
Determines the maximum value of masking applied when ColorMask is on.
ColorMaskCurve
When ColorMask is on, this curve can be used to set exactly how much automasking is applied to various color gray intensities.
Topological
When the Topological button is activated on any brush ZBrush will respect the topological flow of the mesh. Prime example would be opening or closing a characters mouth. With this active ZBrush will not effect the lower lip of a character when the upper lip is being worked on. The Topological Range will be vital in evaluating the topological flow of a mesh when this button is active.
Range
The Range slider will determine the distance ZBrush will evaluate along the topology of a mesh when calculating points to be effected by the selected brush. If the setting is 3 then ZBrush will evaluate the mesh 3 times the selected brush size to establish a range of vertices points that will be effected as the brush is moved along the surface.
Smooth
The Smooth slider will determine the distance ZBrush will evaluate along the topology of a mesh to effected by selected brush. If the setting is 3 then ZBrush will evaluate the mesh 3xs the selected brush size.
Reference Guide > Brush> Auto Masking