How do I make pinning follow a model? What object should I select for the hook modifier? In my case the origin does not move. There are only rotations. I am tracing the image series of a running human by Eadweard Muybridge.
You can use an empty with vertex parenting:
Select a vertex on your non-cloth object and press ShiftS > Cursor to selected
Switch to object mode and add an empty (ShiftA)
With the empty selected (orange) and your non-cloth object active (yellow outline), enter edit mode and press CtrlP > Make vertex parent:
Back in object mode parent the cloth object to the empty by first selecting the cloth object, then the empty, and pressing CtrlP > Object.
Result (click for html5 video version):
The object in the hook modifier is the one you want the cloth to follow. This might be a characters body or you could select an armature and then a bone, such as the neck or hand.
There is a shortcut to creating hooks. Select the object you want to follow then shift select the cloth object and go into edit mode. Select the vertices you want to pin and press CtrlH and select Hook to Selected Object.
If you have an existing hook modifier there will be extra options to adjust the hook settings.
I struggled a lot before figuring this one out:
Having an existing cloth object (the cloth) and sticky object (the object that the cloth will stick to)
for the cloth object
in the Modifiers tab, Move the Hook modifier up, before the Cloth Modifier
Then, in Object Mode Select the empty object, then the sticky object, and Press Ctlr+P, Object (Set the parent of the empty object to the sticky object)
You should then be set