I've asked this question before in other forums without much help, so I'll give you geniuses a go at it.
I've been trying to export a model I made for the last few days with no real results. What happens is that when I try to export as either DXF, OBJ, or FBX (Kaydara's plugin) I have some pieces of my model show up with their normals reversed. No matter what options I set, they always come out that way. When I exported with the FBX plugin, I got an error that said "Following nodes have negative scale values in their default transforms" and then lists a bunch of my model's pieces. This makes sense because I duplicated those pieces and then scaled them to -1 (to mirror them). But even after I've deleted all of the history and froze the transforms for every piece, I still get the same error message. The normals look fine for those pieces, so I'm not sure why it's remembering them as being scaled to -1 if the normals are facing the way they should be.
What confuses me though is that even after I freeze the transformations the normals are facing the correct way. But when I export the model, they come out backwards. I am positive they are facing the right way as well, because I've tried turning on backface culling to see if they're right, and I've shown the normals and they face the right way. It's quite perplexing.
I have tried the mirror geometry as well. The one downfall I run into when I use the that is that it always mirrors that piece right next to the original. So, for example, if I have a piece at (3,0,0) and I want to mirror it over X, theoretically it should mirror to (-3,0,0). Instead it puts it right next to (3,0,0). Does that make sense? The only way I can get it to mirror over the true X axis (not just the X, Y, or Z axis for that object) is to scale -1 it.
I am lost. Does anyone know of any plugins or MEL scripts or anything that can do what I need them to do? Do I need to triangulate the entire model first? Some people have suggested I just flip the normals on all of the pieces that are backwards, but that's a lot, a lot, of pieces, and there has to be a reason that this isnt working. Please help.