Reply To: the hand is stiff

[Dwayne Savage]

For a character like that, yes you should continue this course, but before doing this course you should complete this course:

CORE Fundamentals of rigging

This should answer a lot of questions for you. Now I’ll try and clear somethings up. 

Think of rig as layers. 

DEF bones are the ones that connect to the mesh. Vertices and/or objects are connected to these bones. When they move something on the mesh moves. It can even be the entire object/mesh. Each bone will correspond  to a different part of the mesh. 

Then there’s the base control bones. In most cases this starts as a copy of the DEF bones and is used as the controls for the animator when they are animating. Basically they move each joint(AKA bone) into position. For example: reaching for a door handle to open a door. The upper arm is moved then bend at the elbow(AKA rotating the forearm). Then positioning the hand. Then wrapping the fingers around the door handle. Control bones use FK movement. 

The linking is that the control bones are parented to each other in a logical manner. For example you want the head to move forward when the character bends at the waist not when the hand rotates. Then control bones are linked to the DEF bones through constraints. Constraints can be turn off thru influence slider or they can be overridden by a constraint higher in the stack. This allows for animating shape keys, corrective bones, situational bones, and of course switching from FK to IK. 

IK setup is only used for areas where It can make animating easier. Like arms and legs. Also along the spin. I believe Wayne covers this in this course. An IK setup is made up of 2 parts. The mechanism bones(MCH) and the control bones. Most of the MCH bones are used to link to the DEF bones through constraints. They are parented to themself and the top parent then is parented to next logical control bone not apart of the IK chain. Like a chest bone for the arm IK. Control bones are usually parented to the root bone or highest body bone. Commonly the hip. Bone. Sometimes this will be setup as switchable. In which case it will have no parent and instead be linked through constraints.