Houdini | Gradient Ascent & Descent - Contour Lines
Now that we know about gradients, there is another concept that's related to them that can be acquired quite easily, and that concept is contour lines.
A contour line (also isoline) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. There are very interesting relationships between the gradients and the contour lines.