For animation projects that demand multiple objects interacting with

each other, an option that can create hierarchical relations between 3D

models will become useful. That tool allows an animator to create a

movement based on a parenting relation between objects.

In Blender, you create hierarchies for animation using the CTRL+P keys

to parenting objects. To make it easier to understand, we can name two

objects in a hierarchy as parent and child:

Parent: Object that can receive transformations and will replicate

all of them to the children.

Child: Object that inherits all transformations from the parent. If

you rotate or move the parent, all children will also receive the

same animation. However, any transformation applied to the child

won't affect the parent.

For instance, if we have a 3D model like the one shown in Figure 7.21,

we can make it work as a robotic arm. All we have to do is adjust the

correct parenting relation between each object.