Fortunatly most people either don't know about bridge, or simply never bothered with it. In theory it's a quick easy way to make a quad-plane between two edges... in theory.
This first image shows the basic geometry, all verts are welded properly and there's nothing wrong with it. Save that the bridge tool was used in it's making.
After pressing '2' to smooth, you can see how the geometry has been pinched.I know for sake of the Game Making elements of the course we're in that smoothing like this is a bit of a moot point. And I agree, but this was a handy way of visualising the issue for you to better see.
Clearing the history doesn't kill this pinching, and tools such as selection of edge loops, cut face, split poly to name a few are greatly affected. When using something like the smooth, which does add geometry the bridge-glitche causes the verts not to be welded. Even though the verts prior were fine.
As you can see in this image, all aspects of the smoothing are fixed and nice. How? Well by doing what people generally have been doing already. By extruding the edge, snapping each of the verts and welding the damn thing yourself.It's pesky, and seems a silly thing to make a habbit out of your workflow. However given the alternative 'bridge' which is intended to be a quick easy way of going about this has such a stupid glitch ... the tedious way is by far the better in the long run.
Anyways thought it worth visualising for people, so they can avoid it in the future and know why their avoiding it. oh and I have found the glitch to be very arbitrary.
