The Loomis method of construction is a technique using simple forms and measured landmarks to construct the human head, in any angle. The method starts with a ball, breaks it into four equal sections with two lines and then uses the created measurements to place facial features.

It is helpful when trying to draw people or characters from any angle

When combined with a knowledge of proportion and anatomy, the concept of the loomis method can be use to construct the body from head to toe. Look at how the artist is building the figure from the inside out. 

The technique can be applied for either realistic drawing or cartoons.

This technique is used heavily in 2D animation. Animators use these volumes to 

A) Keep their volumes consistent

B) Mentally work out how the character is moving in three dimensional space.