Harmony 12 Deformation Chains

I’m using the online documentation to figure out deformation chains in Harmony 12.

Is it possible to have a deformation envelope at the end of a deformation chain?

For example, I have a sample character with head and torso drawings on separate layers.

I have a 2 point (start/end) curve deformation running through the torso. There is a bezier handle at the end point so I can put some bend in the torso.

I would like an envelope deformation on the head drawing. I have the head drawing as a child of the torso drawing, so that the head pivot stays put on the torso through any torso deformations. But, if the head drawing is a child of the body when I draw the envelope, I cannot close the envelope. Alt-clicking puts an endpoint on the Torso’s curve deformation.

If I un-parent the head from the tosro, I can draw the envelope deformation correctly, but the head drawing becomes a child of the curves and offset nodes for the envelope deformation. Parenting the offset node to anything other than a master character peg alters the envelope curve.

Is there way to have a functioning envelope deformation on the head, but still have its pivot be a child of the torso’s curve deformation?

Keep Torso and Head on separate layers, not parented.
Then use a “Kinematic Output” from the Deformation Library.
Connect the “Deformation Torso” to the “Kinematic Output”
and the Kinematic Output to the “Deformation Head”.

This will make sure the Head moves with the Torso.

Okay. I added a Kinematic Output node to the rig, between the deformations for head and torso, as follows:

Torso Deformation Output > Top of Kinematic Output node.
Bottom of Kinematic Output node > Input of Head Offset Node (Envelope Deformations do not have a single node, but nodes for each curve and an Offset node at the top of their hierarchy. Seems like having the KO node drive the Offset made more sense than driving one of the curve nodes)

It works…sort of. When I bend the bezier handle on the torso deformation, the head swings in relation, but twice as far, quickly detaching from the end point, as though there are double transformations happening. The head is really tracking the start or root point of the torso. It’s as though I set up the torso deformation backwards, but I thought I would want the base of the torso deformation to be at the waist and not the neck.

Also, just to see if this was peculiar only to envelope deformations, I ran the KO output to the input of an arm drawing with a simple curve deformation of its own. Same thing was happening - root of the curve deformation on the arm was swinging twice as far as the end point of the torso deformation.

Any idea why this is happening?

Can’t say yet what you’re doing differently ?

If you like, here is a short video demo:
(no sound, it’s all very easy and straight-forward)

Thanks for taking the time to post that video.

I went and made a test rig from scratch with a crude stick figure and it worked as expected.

I will delete the deformations and re-rig my other character again and see if I have success the second time around.

One difference is the envelope deformation in the original file does not appear as a single node, but separate curve nodes which are children of an offset node. Not sure how or why that happened, but that at least is different and may have something to do with the strange behavior.