3D Toolkit - Deformation, Polygroups and Clip Brushes (14/10/24)

 

Deformation

The deformation sub-palette provides ways to sculpt 3D objects using unique effects.

• Tool then deformation to access sub-palette
• To see the updated effects in an object on canvas, you must be in transform and edit mode (selected in the transform palette)
• Each deformation item can be restricted to X, Y and Z axes by pressing the corresponding key.
• Deformation respects masking and polygroups

I practised deformations using the Zbrush demo head.

Inflate Balloon Deformation

To change the axis you're deforming on, use the X Y Z keys or by pressing the X Y Z options next to the the deformation you want to use.

Twist Deformation on Z axis

Twist Deformation on X axis

Here I used a mask to experiment with deformation and masks.

Noise deformation using masks

Polygroups

Polygroups allow you to organize the mesh with visual grouping information. Polygroups are one way to organize your mesh and subtools is the other. Subtools create separate pieces of geometry but polygroups only create separate selection areas. The mesh is still one contiguous surface.

Assigning polygroups

• Make sure polyfame is enabled (turn off line). This is located on the right tray and upon activation it turns on visual grouping information
• To assign a polygroup, mask out the area first
• Ctrl W to assign a masked area a polygroup

Using polygroups

• Ctrl Shift - Isolate polygroup
• Ctrl Shift - Hide polygroup
• Ctrl Shift then drag in empty space - Invert polygroup visibility
• Ctrl Shift Alt - Using hide polygroup in conjunction with mesh visibility

You can mask polygroups quickly using this process

• Enter transpose mode (W)
• Ctrl Shift Click on a polygroup

This will mask all other polygroups

Using the Male model in ZBrush, I assigned different polygroups to the hands, arms and head.

Here I isolated the arms polygroup

Here I inverted the isolated polygroup

Combining polygroups

To combine polygroups, I isolated the 2 polygroups I wanted to combine.

I then went into the polygroups tab in the right tray and selected GroupVisible option.

Mesh Duplication

You can duplicate unmasked surfaces by doing

• Transpose (move) while holding ctrl

Clip Brushes

Clip brushes work differently compared to the other brushes as their operation is perpendicular to the canvas. These brushes are used to cut away areas of your model and slice its borders. They don't change the topology of your model, they only push the polygons based on the stroke applied to your model.

Clip brushes use open and closed curves. The curves will have shadows on one side and these shadows indicate the direction the polygons will be pushed in. You can use the Alt key to change the direction of the shadow.

The clip brushed respect masking!

You can tap the alt key with the clip curve brush to create a curved line that can change direction every time alt is clicked. If you double tap alt, you can make the angle sharp instead of a smooth curve.

When your using the circle or rectangle clip brush, you can hold alt and ZBrush will cut away all of the mesh inside of the shape.

I practised trying to use these clip brushes

TrimLasso 

TrimCurve

Pressing alt to change direction of TrimCurve