We're not really using it as intended but then again TG2 allows what we are doing so we can hook things up in unexpected ways. We are only using the perlin to attain a profile for the strata and all we need is an altitude value for position but the preview window will expect a vector I guess and as is can't really display the effects of the perlin. You can hook in other functions such as voronoi instead of perlin or attach a scalar to change the noise or do as I did (in the initial planet on this thread) and hook in a get position in geometry. Then you'll get a preview but of course you don't have the strata effect. If you change the perlin 3D scalar for a voronoi 3D scalar then you'll see the strata steps attain a voronoi profile rather than perlin. You'll see it's sharper edges. You could use a bunch of maths functions like we did on the voronoi thread to alter the strata profile.
The ideal thing would be to have a changeable positioning input or a choice within the UI of the power fractal then we could do this easily with just one powerfractal node or at least get the strata that way. We'd still need a distorting fractal.