The following updated video shows the data visualization from all four inputs. And calculates the position of the nail. As you can see it is not perfect, but you can also see that it does kind of work >>
This is the original video using the finger cap >>
Instead of attaching the Vdd or Vcc to the finger, one could also have it as a continuous conductive layer mounted underneath or above the knit, separated by perforated foam. Although this minimizes resolution to the number of perforations, it does free the user from the additional step having to wear the finger cap. But in this case I consciously wanted to test this method for a future project idea.
The knit does not need to be kept on a flat surface, I just did this for demonstration purposes and the next Instructable will show how this method can be used to turn the whole glove into a touchpad. And then hopefully the whole body, though the problem I have to solve here is how to isolate against the knit interfering with the measurable continuous resistance by touching back on itself.