I have the value of a function in three dimensions, $f(x, y, z)$, which varies smoothly.
I would like to compute a 3D mesh where $f(x, y, z)$ has a particular value.
Are there algorithms to do this? (And if so, any implementations?)
Note: This is the 3D equivalent of finding a contour of a 2D function, $f(x, y)$: