Here is a gallery with all the images in my post for convenience: http://imgur.com/a/PVsKF
The majority of this character will be swimming, so IK will be the primary way I plan to animate him, as it is the fastest and most intuitive. The character will likely have to hold specific objects and do manipulation with their tentacles so FK is an option that is also part of the rig.
While it was still a skeleton, poses like this http://i.imgur.com/z8eRmqp.png and this http://i.imgur.com/nWPVd3T.png and this http://i.imgur.com/MS6YrG7.png are exactly what I was going for. Perfect tentacle positions for floating in the water, and the direction the arms curved control the direction the octopus was going in the water. However, I realized the problem once I skin weighted the rig to the character and tested it!
While a pose where the legs bent similarly to the original sculpt he looked just fine http://i.imgur.com/v79actI.png , but when I tried to do one with the curve going around the outside it’s a total mess. http://i.imgur.com/IbvfcKc.png The tops of his legs have splotches, the bottom has hearts for suction cups- the entire leg is twisted around http://i.imgur.com/MT1E0bG.png Not being able to do these basic poses limits my rig to half of what it should be able to do via IK.
I would like this rig to be able to do a full range of swimming motion which it falsely appeared to do when it was just the rig. I understand the problem, the rig arm rotates to face the pole target now instead of FLEXING in the direction of the pole target, which doesn’t work due the arm twisting. For a character with an elbow that would make sense, however I am not sure how to accomplish what I want instead of this. I don’t know how to rig it to do what I was originally expecting.
Here is how I have my IK set up http://i.imgur.com/8EjdaOO.png
If I prevent it from rotating somehow the pole target will simply not work at all.
• Perhaps there’s some way I can keep the skin from following the z rotation of the bone?
• Perhaps there’s some way I can get the leg bones to move as IK but have it flex toward a target rather than rotate?
(In either case I’d try to make a switch over influence so I could rotate in the future if needed.
• Maybe the pole target can influence the rotation but maybe I can use some other control to control what direction the leg flexes?
• Other IK relevant suggestions?
I’m not sure how to accomplish getting this rig to work properly. Please help?