The Smooth brush smooths a surface by averaging the displacement of vertices with the displacements of neighboring vertices. This means that the ‘scale’ over which smoothing takes effect depends almost entirely on the subdivision level of the model. High detail such as skin pores would be smoothed at a high subdivision level whereas larger features would be smoothed at lower subdivision levels.
Using Smooth at different subdivision levels allows you a tremendous amount of control of how your model is affected. You could, for example, choose to smooth down a mountain range, yet retain all of the fine detail that was sculpted in, such as creeks or rough terrain.
The image above shows this in action. The process is very simple:
- Set Tool > Geometry > SDiv to a level that gives a good representation of the features you want to affect, but doesn’t show the finer details you want to leave unchanged.
- Smooth at that level of detail.
- Set Tool > Geometry > SDiv back to its highest value to view the result.
Several Smooth brushes
Several Smooth brushes are available with different behaviors. The brushes like Smooth Peaks and Smooth Valleys are using the cavity masking to smooth only the inside of a cavity or the top of the peaks of the geometry, while the Smooth Valance, Smooth Subdivision or Smooth Groups (and others) will smooth depending of the topology of your model.
Select a Smooth brush of your Choice
When clicking on a Smooth brush, you automatically define the new Smoothing brush that will be used when pressing the Shift key. It is no longer possible to select a Smooth brush separately as with the other brushes.
If you need to change the kind of Smooth brush, simply pick a new one. Your selection will then become active every time you hold down the Shift key, until you select a different Smooth brush.
To change the modifiers for the currently-selected Smooth brush, hold down the Shift key and make your changes. (For example, hold Shift and adjust the Z Intensity slider.) These changes will only affect the Smooth brush.
A new Smoothing Algorithm
The Smooth brush includes an alternative algorithm, added to create a better result on the poles of the topology of the model (when a vertex shares 3, 5, 7, etc edges).
To access this new smoothing mode:
- Press Shift and start smoothing.
- Let go Shift without releasing the mouse.
ZBrush will automatically switch to the new algorithm. This Smoothing algorithm is enabled in all the smooth brushes.
The Slider Volume Smooth in the Brush Palette>Smooth Brush Modifiers will control the alternate smooth brush’s strength. A higher number will take longer to smooth out the mesh, but keep in mind this will have a slow reaction on a model with high poly counts.
Smooth Brush Modes
There is a new setting in the Brush Palette under Smooth Brush Modifiers>Weighted Smooth Mode that will change the interaction of how a smooth brush effects the surface. There are 7 new modes with a Weight Strength slider to control the strength of the mode that the smooth brush is in.
- 0 Standard: This will keep the smooth brush set at default
- 1 Stronger: This will increase the strength of the smooth brush to interact with the surface quicker
- 2 Valance: Will give more weight where the mesh has more polygons meeting at one point. For example, if there is a point that has 5 faces sharing that point it will receive more smoothing weight then a point that is sharing 3 faces.
- 3 Subdiv: Will smooth the mesh with same algorithm that is run when you subdivide a mesh in ZBrush.
- 4 Stroke Direction: This will smooth the mesh along the stroke direction only. This is a great way to smooth out your last stroke but not loose a lot of the surface detail.
- 5 Perpendicular To Stroke Direction: This will smooth the surface detail perpendicular to your brush stroke.
- 6 Groups Border: This will smooth the mesh but respect the borders of the groups to maintain that line along the border.
- 7 Creased Edges: This will maintain the creased edge when smoothed out.
Weight Strength: Will control how strong the smooth algorithm will react to the surface for each mode. At lower numbers, the smooth stroke will have less effect on the surface. This slider only works with the Groups Borders and Creased Edges mode. Several new Smooth brushes have been added with new behaviors. The brushes like Smooth Peaks and Smooth Valleys are using cavity masking to smooth only the inside of a cavity or the top of the peaks of the geometry, while the Smooth Valance, Smooth Subdivision or Smooth Groups (and others) will do a smooth depending of the topology of your model.
Note: If you don’t remember which Smooth brush is bound to your Shift key, just press this key and you will see the Smooth Brush icon and name in the Brush palette.