isoparm index

[highend3djojan-]

How the isoparms are indexed along the v direction on an extrudedSurface?
for e.g; for some it varies from extrudedSurface1.v[0] to v[4] while for others, its extrudedSurface1.v[-0] to v[-4]  (if span is 4).
Why its +ve for some, and -ve for others? Whats the logic?

[joojaa]

There is none. the naming is based on how the surface was built you can amke whatever parameter values you wish. Maybe you want to encode sea depth levels with negative values. Who knows.