View Full Version : Flipping Polygons?

12-08-2007, 01:29 PM
Hi. :)

I've never had this problem to this extent and was hoping for some help:

I have an object I'm working on that somehow got many of its polygons flipped inside out. That will happen occasionally somehow or other but in this case I wasn't paying attention because I had a double-sided surface applied to it and didn't notice. That surface was a remnant of experimenting and I forgot it was still applied. Normally I'd never do that while modeling.
So now I have this model with inverted, flipped polygons all over the place in clusters. It's a fairly hi-res mesh and selecting them individually and flipping would take to long. if I have to, I have to, but would rather not. I don't want to make them all double-sided, either.

I was under the impression that the Unify Polys tool would make it so all the normals are facing either inwards or outwards but when I use that it just says "no polygons eliminated" and appears to have done nothing.
Also the Align Polygons tool does nothing except tells me "polygons already aligned".

Isn't there some tool that does what I'm asking here?

Thanks. :)

12-08-2007, 02:37 PM
If the double-sided surface was a distinct surface, you could try selecting the polygons by surface name. If it wasn't, then you're probably stuck selecting them by hand. Good luck.

12-08-2007, 02:58 PM
Yeah, I already thought about that, but unfortunately it was all just one surface, and I had not yet made any point or poly selection sets.
I usually have better modeling habits but I was in a hurry and on a roll.
Oh well, thanks anyway. :)

12-08-2007, 02:58 PM
Yeah, align polys was meant for that job, not sure why it wouldn't work. Are you sure they're just flipped? Sure they're not non-planar and maybe twisted to the point of flipping the normal? Align wouldn't catch them if that were the case.

Try tripling the mesh and see if the normals fall back into place.

12-08-2007, 03:09 PM
I'll give that a try if it happens again, which I'm going to avoid.
I already started over and over-wrote the original mesh. I think it actually would have been more time-consuming, not to mention aggravating, to fix it rather than start over.

Thanks, though. :)

12-08-2007, 03:11 PM
Prior using Unify Polys, try using Merge Points first..

12-08-2007, 04:59 PM
Oooh, good idea Sensei.