3D Animation - An Introduction to Computer Graphics for Artists - page 238

Fig. 13.4 This robot character is animated with the use of a complex rig that controls how the
position and orientation of its parts affect each other. The result is a series of convincing mechanical
relationships between the parts of the character (Model and rig courtesy of Perry Leijten)

with them, the fewer edge loops you have. Low resolution characters will have three
edge loops centered on each joint, medium resolution characters will have fi ve.

13.3.7 Rigs

After a character is skinned properly, a rig can be set up to make the character easier
to animate. Without a rig, animators would have to manually move or rotate every
joint every time they wanted to make a change to a pose. With a rig, the animator
can create controls that limit skeletal motion to within realistic ranges (Fig. 13.4 ).
Rigs can also be used to combine animation types so that by moving one control
object, several connected objects adjust as needed to match the modifi ed rig. For
instance, a rig could be attached to a robot that is fi lled with gears. The rig could be
set up so that movement of a bone causes every connected gear to turn the right
amount and in the right direction to make it appear that the gears are turning each
other in order to create the gross movement specifi ed by the bone movement.

13.3.8 Scripts

A script is a set of command instructions that work within your application. Not all
CG applications have this capacity, but all of the major ones do. Scripts can be written
to do anything you could do in the program without a script, but by using a script
they can sometimes be done more quickly. For instance, if you wanted to animate a