Rigging the ATST model

Rigging is putting joints and bones into a model to enable it to animate in a desired way. It enables you to choose at what point the model pivots and/or contorts from.
As my model is a mechanical machine, ideally I didn’t want any contortion of the extremities as they are supposed to be made out of metal.

Skinning does what it sounds like, it turns the outside of the model into a skin, which bends and stretches around the joints and bones. This is better suited to organic things like arms and legs. I tried it on my model but the movement didn’t look mechanical.

The solution to the skinning problem was quite simple, just not to do it. Instead I parented the joints to the models limbs; to achieve this I had to merge the upper knee joint to the middle leg section as they previously shared one joint between them which made a proper leg rotation imposable. With each leg section having one joint, animation was made possible by animating the rotation transforms. The parenting insured the leg always stayed together.