An other take on Extremis limb regrowth, this time working from the outside-in to avoid the gore factor. The thought was to form a "cage" of nano-structure first, then have the bone and musculature form inside that, finally completing with a layer of skin. This was a tricky concept to illustrate, so I did my very first work in Zbrush. While the figure is just painted, the arm structure I sculpted to match the illustration, then created an "endo-mesh" brush to paint a mask and extract the nano-mesh cage. I also sculpted an ecorche of the arm and rendered out a series of masks to allow me to paint over each layer.