28/01/13 - Bones

In todays session we learnt about animation using Bones and Kinematics. Both of these allow for easier, faster and much smoother animation than would be possible through manipulation of each bone individually.

We were presented with a demonstration of where problems can arise, in this case creating a simple walk animation for one leg without a kinematic solver. We were shown how to create bones and how subsequent bones in a chain are subject to their parents movement. We were then shown how you'd go about animating a set-up like this; through a painstaking process of gradual movement and keyframing for both bones in the leg. The result was less than ideal. We were tasked with attempting the same thing ourselves.

After we had all tried our best, unsatisfactorily, we were introduced to Kinematic Solvers. These allow you to create a fixed point on a chain of bones around which they will maneuver.


There are two types of kinematics:

1) Forward Kinematics (FK)

- Controls bone chain from the top-down

2) Inverse Kinematics (IK)

- Controls bone chain from bottom-up

We were then instructed with the setting up of a Kinematic solver and asked to do the same task of animating the leg, the results speak for themselves:

As you can see the non-kinematic leg (left) pales in comparison to the smooth bend of the kinematic leg (right)

Overlapping Action (Tail)

Chain of bones (Forward kinematics)

Animate rotation

Looks mechanical and unnatural

Offset the rotation by one frame for each bone in the chain

Result gives weight and realism to movement

Making further changes to individual bones can create believable and interesting movements

Bunny Rig

Co-ordinate system (Gimbal/View/Parent)

Example of a well rigged model that uses controls for easy animation.