Hi bigseb,

> Its not that it doesn't work, it just looks bad if I give
> a client a model where some surfaces are the right
> way up and some are reversed.

I see - but how was it that you noticed in Powermill that some surfaces were reversed in the first place, does it show some kind of indicator or coloring of the object side in there? If so then you could use it to do the direction tuning.

Another thing that will help a lot is if you join any surfaces that are just sitting next to each other together so that they are connected by a shared edge instead of just being totally separate surfaces just happening to sit adjacent to one another.

When they're actually joined the whole joined thing will have a common positive surface normal side which still may need to be flipped but you'll only have to flip a big piece instead of a whole lot of little separate pieces.

So it's a good idea to join surfaces together even if you don't necessarily have all the pieces to make a fully closed solid from them.

If you can all the pieces in place to make a fully closed solid that will be best though because you won't have to worry about different possible orientations at all if you have made a solid.

- Michael