I've also downloaded the file here https://www.sidefx.com/community-main-menu/character-workflow-rig-animate-secondary-motion/ [www.sidefx.com]
but then I find out that this complexity is out of my reach.
I noticed that in the rig graph before the IK_ANIMATION node and IK_POLES node, there isn't an ik-chain node so the network does not explicitly assign goals/root/mid and pole vector. It looks like the limb IK with pole constraint is written manually?
1.
I start having difficulty understanding since this part.
From what I learned this part adds the control shape, and construct an inverse foot skeleton (for reasons I don't know). And I don't understand why the forearm and calf node has been offset. Is it been moved to mark the pole location?
2.Next is this part
I can understand that it blends input animation into the control skeleton ( the skeleton with control geometry). But the joint appears in apparent pole vector location is called L_forearm, and the joint in apparent real forearm location is called L_forearm(transfered to reparent control rig)
I test the upstream nodes and found that the foremarm and the calf node got "duplicated" in this Rig Attribute Wrangle node.
It seems that this wrangle only sets the affected point's transform matrix to world orientation but the viewport shows two joints for each of them. How did the duplicate happens? And if we use a skeleton node to check it we can find that the actual skeleton does not recognize the *_forearm_reconstructed_hireachy joint. What does this mean?
3.Then inside here.
I can see that the c_main_offset controller is pulled back while the foot controller's are animating normally in a walking pattern.
It feels like a channeled motion where the main_offset position decides the phase of a feet/hand's location, is that same in this case?
However the forearm and the calf joints are also pulled back, and I cannot understand this as well. Are they functioning as pole vectors and are pole vectors necessary to move along the main_offset controller? I thought it should move with the pelvis or COG?
4.finnaly, this formidable blob of spaghetti noodles.
I have no idea what it is computing.
From its parent's parent's layers behavior, it seems it is acting like an IK and a pole constraint system. For I did not even see an ik_chain node in the outer network.
But inside it, I have no idea what it does.
This fancy tutorial gives us great result, but it is very hard to understand.
