Anatomy of the Human Body.

The best way to think about rigging and animating is to compare your rig directly to the movements, actions and capabilities of the actual human body. The character you make may not be human or even alive but the bi-ped/humanoid shape of it, like my robot and the alien, means that the rig still has to move in certain ways.

For example you can't bend your elbow past 90 degrees otherwise it'll break. This goes the same for the alien and the robot. This wouldn't necessarily apply to all robots but if there was no structure to their skeleton their arms and legs would move all over the shop.

This isn't exactly medical journal standard of explaining but the point is that in animation you have to learn the rules to the way bodies move and how physics affects them, before you can break them and start exaggerating and changing them.

Its also worth noting that despite its humanoid shape my robot is very different in terms of how it works. The muscles in the human body expand or contract to do different jobs, the robot doesn't do this as it has no muscles so relies on its mechanical grip. The robot also stands perfectly upright and is perfectly balanced unlike humans who rely on fluid in their ears to maintain a sense of balance. You can also see about that the human knee if, if you followed it directly down, reaches the start of the toes where as my robot its knee is perfectly in line with its ankle. This explains that people are more nimble due to their ability to move quickly in different directions. The robot would be more sluggish in this way and i hope to capture this in the animation.