A Biomechanical Character - ZBrush Creature Design: Creating Dynamic Concept Imagery for Film and Games - page 350

3. Make sure to place the torso back from the head, leaving a good space between the two forms. Note
the negative space from the side view between the head and shoulder/carapace structure ( Figure 6-19 ) .
This area will be filled with mechanical parts later to add interest to the space and give the impression of
mechanization. By allowing the negative spaces to remain here, it reinforces the fact that this is a head
attached to a machine and not a man in a suit.
Figure 6-17: Pull the back of the ribcage up into a carapace behind the head.
Figure 6-18: Shaping the carapace with the ClipCurve brushes
Figure 6-19: Negative space between the head and shoulders from side view