136 chapter 4 ■ ZBrush for Detailing
If you had used ZAdd instead of ZSub, the alpha would be white on black. This is impor-
tant to note. If you had used a combination of both ZAdd and ZSub, ZBrush would record
the depth of the plane as 50 % gray. This is because it’s compensating for pushing out as
well as in. This is an acceptable way of making an alpha. However, you will have to use a
radial fade; otherwise each alpha stroke will have a visible border when used on a model.
You can remedy this by adding a radial fade with the Rf slider under the main Alpha menu.
- The canvas snapshot is now loaded in the Alpha palette. Since it captures black strokes
on white (ZBrush sees subtraction as shades of gray beneath 50% gray), you need to
invert the alpha. Under the main Alpha menu, click the Invr button. We’ll now reap-
ply it to the canvas. Undo your previous strokes or create a new Plane3D so you have a
clean surface on which to sculpt. - With the Standard brush selected, pick the DragRect stroke and your new alpha. Click
and drag on the plane surface to watch your alpha draw. As you now know, any surface
texture that you can sculpt can be captured as an alpha. To save your custom alpha,
from the main Alpha menu click the Export button. Save the alpha as a PSD file.
Details and Layers
ZTool layers in ZBrush are found under the Tool menu. Do not confuse them with the main
Layer menu, which applies only to 2.5D illustrations and is found at the top of the screen. The
Layers menu allows you to store shape changes, sculpted details, and even polypaint in sepa-
rate layers. These layers can be turned on and off or even blended to combine new effects. They
are powerful tools for helping you to control how each aspect of your character’s sculpting,
detailing, and color is applied.
The Layers menu under Tool is different from the main Layer menu. The Tool → Layer
menu is for sculpting details on a Z Tool and storing the details in a layer. These are
saved with your Z Tool file. The Layer menu is only used in 2.5D illustration and cannot
be saved with a Z Tool. Consider these more akin to Photoshop layers that happen to
also have depth control.
As you start adding details to your sculptures, you may want to isolate your detail
passes on separate layers. With details isolated in layers, you can turn the details off and
experiment with new variations. You can also adjust the layer intensity and fade the sur-
face details if they are too strong. In this section we’ll add two layers to the demo head and
adjust their intensities.
- Load the demo head ZTool from the ZTools section of Lightbox. Subdivide to the
highest subdivision level (Figure 4.34). To create a new layer, click the New button on
the Layers menu shown in Figure 4.34. With the layer selected, click the Name but-
ton and name your layer sculpting. By default, any new layer is set to record—you can
note this by the small REC icon beside the layer name, as you can see in Figure 4.35. - Use the Move brush to change the shape of the head (Figure 4.36). Changes you make
to the mesh are stored in the sculpting layer currently selected and set to record no
matter what subdivision level you are on. Changes will continue to be recorded by this
layer until you disable recording by clicking the eye icon at the right of the REC icon.
Figure 4.34 The
Create New
Layer button