Posing the Interdimensional Traveler - ZBrush Creature Design: Creating Dynamic Concept Imagery for Film and Games - page 210

While composing the image, be sure to keep the implied lines in mind. These are similar to the gesture
lines of the figure. Figure 4-35 , for example, shows the arm at a right angle. This creates an unnatural break
in an otherwise organic form. Bend the arm out slightly to create an implied line that flows down the figure.
Figure 4-35: Note how the arm is improved by breaking the 90-degree angle and introducing more of a
curve.