3DS Slicing animation and Unity

I have a complex 3D object that has multiple layers. I’d like to be able to show a cut away slice of it so that the player can see the inside of the object, so I created a slice animation in 3DS and exported it to FBX only to find out that it does not work.

I then went and did a little research and found that Unity animations must include bones in order to work. Is this still true? Do I have any other options where I could get this to work?

Is it at all viable for your game to split the mesh into pieces and then just hide the parts that you don’t need?

Better yet: Move the unneeded parts out of the way slowly. It looks cool.