I am trying to do facial rigging for an eyebrow using a curve. There are three joints skinned to a curve, and then I added to the curve to the influence of the main model’s skin cluster. Although when I paint the weights for the curve it does not effect the vertices at all. The curve shows up in the list for the model’s skin cluster, and the component editor shows the vertices as having influence for the curve. For whatever reason when I move the curve using the joints they are skinned to nothing happens.*
The skin cluster use the influence object’s transforms (translation, rotation, scale) to effect the deformation of the vertices of a shape, when you deform the curve with the joints your effecting the curve’s shape, not its transforms.
What you want to use is a wire deformer or, for better control, you could attach joints to the curve using a motion path node and add the joints to the skin cluster - that way when you deform the curve it would effect the transforms of the joints which would effect the vertices of your mesh
A curve can be used to skin as an influence object, you may be missing setting to the option to same as below,
As shinyprem pointed out, you need to turn “Use components” to 1. Also, I don’t know for what are you planning to use it, but I woulnd’t stick too much to that one as it can give you more cons than pros. Had tons of “Why did I even bother using components”. It can give you some really fast results, such as using 2 ribbons as influences for fast lips skinning etc, but personally I wouldn’t use geometry as influence at all. Using it to drive deform joints is something I would aim for.
All the best,