
Then the penny dropped for me - 2D animators don't see the fully shaded character in the lightbox when animating, they see only the lines they've drawn, so the spacing is a lot easier to see.

One problem is that they slow the scene down usually, and another is that they are not that easy to see in the viewport, usually being a faded version of the mesh or a wireframe of it which doesn't read very clearly. I realised I feel the same way about any 3D ghosting solutions I've tried. He mentioned a couple of reasons why he usually doesn't, even though he uses the lightbox feature all the time when animating in 2D.

I was watching a recording of a live lecture with Jason Ryan (Dreamworks/iAnimate) when a student asked him if he used ghosting when animating in 3D. This is an animation tool I wrote for Maya that provides a different approach to ghosting/onion-skinning in 3D.
