To increase the tessellation on your model you will want to increase the tessellation quality settings in your CAD software. When you import your model into KeyShot, you can expand the advanced menu and change the tessellation value. Usually, this is set at 0.5 by default on a scale where 0 is the minimum and 1 is the maximum. For some plugins this tessellation slider is found under the plugin settings.
SolidWorks users, please note that using the new importer will only take the tessellation value specified in SolidWorks and disregard the tessellation slider in KeyShot. For some Creo engineers, the regenerate command does the trick. Alias adepts importing wire files will want to enable “Accurate tessellation” to obtain that extra oomph .