Special effects are generally described as effects that can be done
while the scene is being captured and are commonly called
practical
effects. Special effects go hand in hand with visual
effects in current methodology, such that it is often difficult
to determine what was a special effect and what was a visual
effect. This collaboration has been enhanced by digital technology.
For instance, the early acceptance of digital rig removal
allowed more freedom for special effects artists to create more
elaborate flying rigs on set while greatly increasing safety for
all involved. Examples of more typical special effects are bullet
hits, practical explosions, rain, fire, car gags of all sorts, flying
rigs, motion rigs that shake sets or props or vehicles, gimbals to
mimic the motion of boats or planes, and artificial ocean waves
and spray.