[bug] Rail variations don't use consistent index

[d3x0r]

I was making some images for rails that go across water; with shadow.
I put the shadow on stone-path-background layer, and the poles/frames on stone-path.

The original image has the diagonals aligned... but the poles aren't nesseciarily exactly in the same place in every variation... so sometimes the shadow and the poles don't align.

Notice the shadow at the base of the poles....

bad-shadow.jpg (24.69 KiB) Viewed 542 times

This is the original image (with all variation slots) (only merged wood frame, shadow and mask overlays, no ties or rails)

good-shadow2.jpg (9.95 KiB) Viewed 542 times