Figure 7.25 - Object constraint
After adding a constraint to an object, you will have unique options for
each constraint type. The panel works like options from modifiers, where
you can manage and reorder constraints applied to any selected object.
Among constraint types available, you will find:
Copy Location, Copy Rotation, and Copy Scale: Makes the
selected object using the same transformation data from the
target object.
Limit Location, Limit Rotation, and Limit Scale: Makes the
object chosen to receive a limit for each transformation based on a
target object.
Child of: You can create parenting relations that can receive
keyframes.
A key component of all constraints is the Influence option. With the
influence, it is possible to set how each constraint affects object motion.
An influence of 1.000 means it has a 100% impact on the motion. By
dropping that value to zero, it is possible to "turn off" a constraint.
You can easily add keyframes to the influence settings, by placing the
mouse cursor above the influence field and pressing the I key. That
opens a world of possible animations we can create using constraints.
7.6.1 Making an arm grab an object
An easy example of what we can do with animation constraints is
making an arm grab an object. To make our example simple, we can use