Layered modeling also transcends visible surface modeling to produce 3D solid models comprising closed volumes, bounded by surfaces and curves, an area thus far dominated by traditional CAD based solid modeling techniques. We note that designers often draw a number of curves in a closed loop that defines a shell-like surface patch implicitly sandwiching a volume with the underlying geometric layer (Figure 1(b)). We are thus able to infer and create 3D volumes along with their bounding surfaces and curves automatically, from a few closed design strokes (Figure 1(d). These 3D volumes, bounded by 4-sided spline patches are easily represented using hexahederal elements suitable for further physical deformation and simulation.