This latest and most excellent plugin, TopoShaper by Fredo6, generates Terrains from iso-contours, that is, contours which have a constant or quasi-constant altitude. Often, when generating terrain with the Sandbox > From contours tool, it has smaller of bigger faults, the generated terrain is not even and smooth and can look (let's face it) "ugly". TopoShaper generates beautifully even terrains based on quads which will look excellent in any application you may wish to render them.

Please, read the forum topic on how to install and what other requirements are carefully.