I've been watching a box head modelling tutorial today where they guy (using silo - which btw looks like a really fluid workflow) sets up a mirrored copy of his model that auto updates as he makes changes to the real / opposite side of the model. I know this sort of thing can be achieved by making an instance of the first poly and then just editing the original but he also had another interesting feature that I'd like to replicate.
In the video the centre line between the two meshes was sepcifically defined in some way and acted as a merging point between the two sides - polys dragged toward the line didnt overlap it, they simply combined together.
Here's a pic of an inset being applied to right (real) side which is then dragged to the left and fuses with the copy model.
[Blocked Image: http://i29.tinypic.com/11sgvf5.png]
I'd be interested to know if a similar feature existed in max and if so, how to go about setting it up.
cheers