4/8/10

A.L.F.R.E.D. - Rigged With Controls

Continuing on in the world of ALFRED, I finally was able to get him rigged up with controls. When doing animation, it would be nearly impossible to do anything of worth if you had to go in and select each piece individually and change its values. Searching through everything, for one, would take forever and you could never find anything. (It's the equivalent of reaching under the hood of your car while you're on the freeway just to control the throttle.) Secondly, it is frowned upon to do any keyframe animation on a skeleton itself, like with what I set up for ALFRED last week.

That's where creating animation controls comes in to play. In the following video, you will see a playblast of ALFRED all rigged up. Surrounding his body are a number of circles. Each of these circles represents a controllable body part, such as the ones surrounding his head, neck, shoulders, etc. This allows for quick selection of those parts and also means that I don't have to go digging for the skeleton to animate it. There is a special piece of programming attached to each of these 'controls' that tell them to rotate each joint accordingly.

Also, ALFRED is set up with both Forward Kinematics and Inverse Kinematics. These are just different ways of controlling how things work in an animation rig. For FK, every joint down the chain of a skeleton influences the next one. For example, if I wanted ALFRED to reach up and scratch his jaw, I would first rotate his shoulder, then his elbow, then his wrist, then his fingers, etc. In IK, this means that the joint further down the chain influences those that it is programmed to upwards in the chain. For example, if I wanted to animate ALFRED in a walk cycle, much like I did Norman last semester, It would be a pain to have to rotate the hip, the knee, the foot, and so on every time I wanted to get things right. Instead, I create a controller for the foot and set up an IK Handle between the hip and the ankle, and then create one between the foot and the end of the foot. This then means that wherever I drag the foot controller, the rest of the leg will follow.

Mainly in animation you want to animate a character's arms with FK and their legs with IK. Arms don't really need to be IK unless they are holding onto something or the rest of the body needs to move independent from them. I set up the controls on ALFRED to be able to switch between FK and IK in his arms, just in case I wanted to switch in an animation. Anyway, enough white paper. On to the freak show:


I also wanted to point out the concept of ambient occlusion, which I did on this video. Essentially, ambient occlusion is a way of simulating the phenomenon of light not being able to reach certain crevices or surfaces. It typically creates a much more realistic rendering when you include it in your animations, although it does take time to compute.

1 comment:

Elder Max and Sister Pat said...

Looks great. I can't wait to see the 30 minute version or at least the final version for this class.