So far we have been sculpting characters with a focus on primary and secondary forms—that is, the skeletal anatomy, the muscular anatomy, and the major forms of fat and flesh. The first three projects lack any kind of fine tertiary details. This was intentional because I wanted to illustrate that form is the most important consideration before you start to detail your character. Good form is what makes the sculpture believable, not pores and wrinkles. High-frequency details on top of bad form will do little to help the overall effect of the sculpture.
In this topic we’ll take our sculptures to the next level by adding fine tertiary details. We’ll discuss alphas and strokes, and also look at ways of creating your own alphas from existing photography or sculpting them from scratch in ZBrush. Finally, we’ll explore the dynamics of wrinkle patterns and how to create natural patterns on the skin.
Form can be broken down into three categories. The primary form represents the largest basic shapes of the character. Secondary forms are muscle forms and folds of flesh. Tertiary details are things like pores, fine wrinkles, and scale details. For a sculpture to work, the primary and secondary forms are the most important.The tertiary forms are just icing on the cake and cannot make a bad sculpture good. Figure 4.1 illustrates these three levels on a single character.
Figure 4.1 These images illustrate what constitutes (left to right) primary and secondary form and tertiary details.
Once you have the form established and the character works without detail (Figure 4.2), you are ready to use ZBrush’s alphas to add the fine details for which the program is so well known. This is where the ability to subdivide into millions of polygons matters most. Figure 4.3 shows a mummy sculpted by ZBrush artist and sculptor Alex Oliver. Notice how the details in this mummy serve to support the overall character.
Figure 4.2 The Stingerhead character, pictured on the left with only form addressed and on the right with the addition of tertiary forms. Notice that the sculpture works even without the fine details.
