LoopTools lofting tool chaotically "reversing"

I am using the LoopTools add-on to loft simple curves (near-parallel) into simple surfaces, but in certain cases the tool chooses to match the vertices at the opposite ends of the curves (the equivalent of choosing the “reverse” option), returning a self-intersecting mess instead of the simple sheet I expect.


often-obtained output:
desired output:

Both above results were obtained using the Bridge tool (equivalent output from Loft) with the “reverse” setting off, using linear interpolation for one segment.

If I play with the number of segments it often flips back and forth between “correct” and backwards". Choosing “reverse” sometimes flips the curve, but sometimes not, and sometimes clicking it twice (on-off) will fix the problem.

Does anybody know what is happening here??

I use this tool extensively in an add-on, so I need the proper surface to be generated consistently from a standard set of parameters. Thank you for your help! (Blender 2.74)

And attached here is the sample .blend file for the above example in case anybody wants to fiddle.
bad_curves.blend (543 KB)

Thanks again.

If you convert the mesh back to a curve (Alt+C), then reverse the direction of one of the curves and convert both back to meshes, it works like it should, even though both curves seem to point in the right direction from the start.

Thanks Klutz.

I am given many similar curves as input, and I need to know how to manipulate them so that the lofting always works. Does anybody have any idea what the condition is that causes this strange behavior to occur?

Alt+c -convert to mesh,then “bridge edge loops” works(no need addons)

Remade - you’re right, for what I am currently doing, the Bridge Edge Loops tool is sufficient, and I will go ahead and stop using LoopTools for this task. Thanks for the suggestion!