[Animation] Deconstruction: Frame by frame and inbetweening.

If you haven't seen my previous entry, I'm going to start making posts where I deconstruct animation I've created. These posts are going to be a mix of tutorial and personal reflection. Some of the techniques I bring up may have different names, or not even be techniques at all, I'm just explaining my findings as I progress.

In Flash, I find there are dominantly two core forms of animation, symbol and tween based, and frame by frame drawing based. The previous entry gave some brief tips on getting the most out of symbol animation, so in this entry I'm going to explain some techniques I used in the small clip above.

This clip is built in three basic stages, anticipation, action and reaction. See the three blue drawings on the left for the keyframes. These are core for making many movements look interesting and less mechanical. Anticipation is the movement leading up to a motion, usually in the reverse motion of the intended motion. In this case, the anticipation is the duck towards the book, a downwards motion that then leads into the looking up motion. The next stage is the action itself, in the case of this clip that's the looking up motion. Finally, the reaction. This is the "follow on" motion, which is usually hair or drapery (clothes) for me. This stage helps the movement bounce, rather than stopping unnaturally.

Once these three keys are sketched, it's on to the mapping. By this, I mean planning out how each part of the body will move. In an old test I did, I sent out some keyframes for people to inbetween. In the results, a lot of people literally drew the middle position. This method really doesn't work with motion as the animation looks awkward and has no depth to it. Instead, I've started animating each part of the body separately. In this case, I first animated the legs, as they are the top layer. Animating things separately creates an offset effect and breaks up the motion, rather than having everything stop at once, everything has it's own individual timing and rules. By the time this is done, you should have something like the second clip, with all the solid sections inbetweened, following the three stage rule on their own timing. The final step is to add drapery/hair. This acts to break the motion up a little and create an overall reaction stage. In the Animators Survival Kit, the rule says that drapery always stops last. You can see that effect in place on this. As the head drops down, the hair continues that motion. As it starts to go up, the hair has a delay before following this movement and bouncing back up. Finally I added a bounce at the end just as an extra reaction stage and to add some more life. The next stage will be colouring. For now I've used flat colours, I'll explain cel shading in a future entry.

**EDIT**

One final technique I forgot to mention is the opposite movement between the head and the book. This subtle technique just puts more space between them in the action, adding more of an impact to it.