smooth voxel terrain tutorial?

just started unity. i cant find a smooth voxel tutorial on youtube, only minecraft style block voxels. i want no mans sky style terrain with similar mining and terraforming. can someone help put me in the right direction please? ive seen marching cubes get brought up. but again no good tutorials. i want to have a basic destructible smooth voxel terrain to be done first to do all my tests for the terrain and to work with characters on it, etc.

There’s this video I Made Minecraft Without Blocks - YouTube from Sam Hogan, which he transforms his Minecraft game into a smooth terrain without blocks, you can download his code and test. There are also videos from Sebastian Lague about these topics.