DESCRIPTION:

Enable or change the amount of "finestepping".
If this is off, the renderer may take several shortcuts
that allow faster rendering at the expense of slightly
inexact borders. This is usually acceptable, but when
recording movies with low step widths, it results in
flickering and waving borders.
In some renderers, it can also be used to tune overall
render quality, as it then gives the number of steps
taken to find the exact isosurface crossing point.