Mesh outer layer of voxel set not representing a distance field

[pbarendrecht]

Given a voxel set whose outer layer of voxels does NOT correspond to an isovalue (e.g. the result of subtracting two partially overlapping voxel sets, or similarly, clipping a voxel set to restrict it to a certain region), is it possible to mesh this outer layer?

If we treat such a voxel set as a Boolean voxel set, this should be doable (e.g. using marching cubes and — optionally — subsequent simplification/decimation). Unfortunately, there does not seem to be a VolumeToMesh method that does not rely on an isovalue.