How is the typical trans (or texture) map applied to hair?

rbel_295e7c1d4c

The trans file image is usually made up of a series of vertical strips of varying lengths with feathered bottom edges, not an image of the hair in its entirety. How is this applied to what can be a large number of hair segments?

Richard Haseltine

Applied? By selecting it in the Surfaces pane for Opacity strength. If you mean why is it like that, modelled hair is usually made up of a number of overlapping sheets, which are unwrapped to lay together on the UV map and that's what you see when you look at a texture or opacity map.