Anchoring the ends of a spline ik system

Rigging
1

I’m rigging a creature that needs to walk around on tentacles.
My Art director has requested the ability to animate nice s-curves in the tentacles as well.

Walking around -pinning the ends to the ground- requires IK
But the s curves usually use a spline IK which leaves the end bone flailing about
Is there a way to anchor the ends of a spline ik system?

I’m using 3DS Max but perhaps Maya techniques would translate…

2

What i’ve done in the past:

  1. create a traditional bone rig for the ‘limb’ version
  2. skin a linear spline to the bone rig
  3. create a smooth spline from the linear, leaving the construction history on so that the smooth spline follows the linear spline
  4. Add deformers to the smooth spline for ripples, etc.
  5. use spline IK to control the real skeleton with the deformed ripply spline as the control IK
3

in maya i would make the spline ik and create as many controls as needed for the animtor
to ensure that the spline will be anchored on both ends i make the bones scale to ( size of the spline/ number of bones )
and depending on engine capabilities is skin to these bones or i just parentconstraint new bones to these to avoid scale issues ingame

might even attach this intire rig to a 2bone ik system for easy planting on the ground

4

You could use a ribbon spine rig. I also do what Peerke88 does as well. I’ve found both options to be good enough to keep me employed, but I would like to one day make something a bit better. I’ve never used it myself, but I’ve heard of something called the awesome spine rig