Not sure the actual process is doable in practice. I mean, you’ll probably have to mask it using some neat graphism, but slowly cutting the mesh… An object has a lot of tention between its parts, when you cut it, the tension disappearing is what causes the “ripple” effect. In UE4, they are just meshes, so even if you cut it, unless you apply some force which actually causes the mesh to break up slowly, you’ll only see the sword going in, like if it was overlapping, but you wont get a true slow-mo cutting effect.
Does this make sense?