How to "stick" an object to another such that it follows during animation I am trying to animate a swimming robot. It looks like this
I can easily calculate the centers of the spheres during one swimming strokes and set the keyframes accordingly. Now, is there a way to &quot;stick&quot; the jacks to its two corresponding spheres such that it deforms during the animation? The idea is that the spheres always stay connected. In reality, the arms would elongate and retract. More precisely, the spheres move along the axis defined by the jack around some initial length, while the whole structure translates and rotates.
You may want the cylinders to keep their shape when the spheres are moving.
First approach: cylinders follow spheres

A way to do that is to use bones and a &quot;stretch to&quot; constraint for each bone:

The vertices of each cylinder are linked to there bone's group name.
Each bone is placed along its cylinder.
And each bone as a &quot;stretch to&quot; constraint to the sphere (with &quot;maintain volume&quot; to none in order to have no deformation of the diameter).

Second approach: spheres follow cylinders
If you prefer to rig/animate the cylinder and make the sphere follow, you can use a &quot;copy location&quot; constraint to the spheres:

For each sphere, indicate the armature to follow, then the bone and set head/tail ratio to 1 so that the sphere follow the tail of the bone.