I know this is a really old thread, but I kind of wonder what come of some of these questions, because I still find that ROTSTEP output isn't always what I'd expect. But maybe I'm expecting the wrong thing.
Basically, as I understand it, the difference between REL and ADD is that REL combines the rotation given in the meta with that of the default view, whereas ADD combines it with the current view. So if you are on the first step of a model and you add either a REL or an ADD statement, you should get the same result because the current view is the default view. (Assuming ASR is enabled and you haven't manually changed the view.)
But that's not what happens. Say I have the default view set at [30 -35 0]. Now let's say I want it to be [35 -35 0] instead. I can get that with a [5 0 0] ADD statement. But if I use [5 0 0] REL, the resulting view ends up being [36 -35 4]. Huh?
Basically, as I understand it, the difference between REL and ADD is that REL combines the rotation given in the meta with that of the default view, whereas ADD combines it with the current view. So if you are on the first step of a model and you add either a REL or an ADD statement, you should get the same result because the current view is the default view. (Assuming ASR is enabled and you haven't manually changed the view.)
But that's not what happens. Say I have the default view set at [30 -35 0]. Now let's say I want it to be [35 -35 0] instead. I can get that with a [5 0 0] ADD statement. But if I use [5 0 0] REL, the resulting view ends up being [36 -35 4]. Huh?