File:Gravitywell with ellipse.jpg

Summary
surf[{x_, y_}] := -Exp[-.5 (x^2 + y^2)] ; (* surface *) curve[t_] := {0.5 + 2 Sin[t], - 1.5 Cos[t]} ; (* curve(ellipse) to plot on surface *) plot1 = Plot3D[surf[{x, y}], {x, -3, 3}, {y, -3, 3}, Boxed -> False, Axes -> False] ; plot2 = ParametricPlot3D[Flatten[{curve[t], surf[curve[t]]}], {t, 0, 2 Pi}, PlotStyle -> {Thick, Red}] ; plots = Show[ plot1, plot2 ] Export["C:\\junk\\plots1.png", plots]
 * Other information: