Lately I was learning a lot about animation with so called inverse kinematics – a technique that is available in newer versions of Flash.

Your character has to be made up of separate elements – then you can use the “Bone”-tool to construct a skeleton for your character. You have to define the bones, joints and rotation limits. After that you can animate your character like a puppet: just move the toe tip and the rest of the leg will follow.

With this technique you can then animate in the timeline – simply add keyframes and alter the pose of the skeleton. An other possibility is to set the animation to runtime – then the user can interact with the character via click & drag. Below you find an example of both possibilities:

Timeline Animation 
Runtime Animation (drag the body parts)


Bone Setup

Flash is pretty smart and detects the body parts automatically when you construct the skeleton above it – but be aware that all parts have to be converted to symbols. Each part can just have one bone assigned to it. That is absolutely fine unless you need some more control to the last part of the bone chain (like setting up angle limitations for this joint). There is a pretty simple way around it: just setting up an extra object on the end which is invisble.

Don’t let Flash confuse you: It automatically rearranges the order of your parts. After setting up the skeleton you have to reorder them, so they are layered correctly.

If you have got any questions please feel free to drop me a line in the comment section.