k3d/share/shaders/k3d_strata.sl:11: *    turbscale - how turbulent the layers are
k3d/share/shaders/k3d_strata.sl:38:		   float yscale = 2; float turbscale = 0.1; float offset = 0;
k3d/share/shaders/k3d_strata.sl:57:  cmap = yscale * ycomp(PP) + turbscale * turb - offset;
