Quote - I think you mean that getting the streaks to follow a specific curved path is not easy, and that is absolutely true. But Mark didn't ask for that.

In the use case involving this particular hair, the bottom layers are not strictly vertical or horizontal, and procedurally streaking them is a fail.

However, many hairs have two different materials for outer and inner layers, and streaking the outer layers where all the strips are straight is perfectly dealt with here.

 

That's exactly correct. The curved piece of hair in the middle of the example texture map shown above is meant for the scalp piece under an outer layer of longer hair. It's the outer layer I wanted to randomly put streaks or highlights into.  From what I've seen this is a pretty common approach to setting up hairs, so I think this will work fine, I tried it last night and it looks pretty good. The inner scalp layer is usually only seen at the front hair line above the forehead, and only a very small area is exposed.

 

Perhaps one question I had as pertains to scaling, so let me see if I can phase this correctly. The new streaks apply over the hair texture map, but say I wanted something denser, more streaks per inch. As one extreme example, say I completely eliminated the hair texture map and wanted to show individual hairs. Many more streaks per inch would be required than for the "highlights" I was adding previously. How do I control that density? It may be I don't understand how Poser applies the little map I see at the bottom of the node to the hair texture map. I know the hair map is physically large in terms of dpi by dpi because I can look at outside Poser, but the little "preview" image for the steaks is hard to see. How do I know I'm really adding more streaks by some method? I don't see that there is any tiling option, so control of the density of streaks is unclear. I can see how to make a few big streaks as you outlined last night, but again how does that scale match the scale of the hair map or the object being mapped to? Is that only to be understood by trial and error (try it, render it, change, render again, etc.)

 

I was told once, if you don't understand, ask. I've always followed that guideance to the point of asking very simple questions some times. I understand this is trivial to talented people, but it helped me, so I appreciate it. I have to leave for work, so I'll be off line for awhile.

 

Thanks again