Paddling a Boat with BOTH Hands...

Hello, I am currently trying to get a model to use both hands to paddle a boat. This IK controls worked initially but when I parented the full rig to the boat (since the boat will be moving in the water) it got extremely glitchy! If anyone out there has any good insight or perhaps a better way to go about this I would be very grateful! I have tried different constraint settings but can’t get anything to work. If you have time to look at the file you can find it here…

Thanks in advance to anyone who has anything to offer!!

My quick thought is to have empties as the IK targets for the hands, parent these to the paddle in two locations. Then move the paddle to animate the arms/hands. I do not have time to look at your file just now - maybe tomorrow or Friday. It is important if you have more than one IK chain in an armature that you set the chain length to cover only the bones required, i.e. not 0, this may be the issue, I’ll let you know after I look at your rig.

Cheers, Clock.

Thanks… that is exactly what I did when setting it up, and it worked fine. It only messed up when I parented the entire rig to the boat. I wonder if there is a better way to get the rig to go with the boat but not sure what that would be. Thanks for responding!

Hi, you can try constraining (child of) the character to the boat instead of parenting it.

thanks clockmender. that is exactly what i did and it worked like a charm until i parented the rig to the boat. harumpf!

thanks Hadriscus. i did try that, unfortunately it led to the same problem.

You have your chain length on your IK set incorrectly. Each hand IK is going all the way back to the root of the rig-- meaning if a hand moves, the entire body will too. It needs to go to the shoulder or clavicle, then you animate the rest of the body movement yourself … or with IK’s on separate bones, but generally never going all the way to the root unless it’s the head (but even then, probably a bad idea).

You have it set to… 50. Haha. It needs to be at 4 (to reach the clavicle). Change DEF-hand.R and DEF-hand.L’s IK chain length to 4.

Also… turn on the ‘Relationship Lines’ in the viewport to see how this works while you change the chain length… I highlighted it in the above picture.

Then remove the parenting of the armature to the boat. Select the rig and set to object mode, and click:

After you do that, add a ChildOf constraint to the ROOT bone and constrain it to the boat (make sure you are on the very first frame when you do this) and press Set Inverse.

Now play your animation… magic!

PS. You should never parent the entire rig to an object. Use a bone constraint in pose mode for that (root bone). And in the future, make a rig for your boat. A single bone…

Thank you so much MurrayTORONTO! I originally had the chain length much lower but changed to to the outrageous 50 to see the effect it had. Obviously I still have a lot to learn about IK constraints! I do really appreciate you taking the time to look at this, since as you probably know Blender can be thoroughly frustrating to figure out on your own at times. Again, that you to all that took the time! Hopefully this time tomorrow I will be able to report back with success. :slight_smile: