partial torus prims

[N. W. Perry]

something like this? (screenshot from LDPE edited with paint)

the addition itself:
t08o800 like the existing syntax
the +/- indicates from where to start
the number states how far to go (+100 would be the same as a -100, a full quarter, no suffix needed then)

usage:
could be useful for chamfers or partially prints
if a torus gets cut somewhere
-> could still apply to prim subst

I have read over (several times) the various suggestions, but I return to this as the most elegant solution so far. It is subject to a couple of problems that have been mentioned…

We really only need to know two things:

1. how many segments of the minor radius (the tube itself) there are, and
   
2. whether we're counting from the plane of the major radius or from the perpendicular axis of the tube.
   

For #1, I'm ok with using a percentage or ratio, since we already do that for the ratio of the minor to major radius. But to Travis' point on that, there is probably a simpler way. I propose using the number of digits to signify the resolution (16 or 48), and then just use a cardinal number to that many places. In other words, a 16-res tube will always have a one-digit value of 1, 2 or 3 (since 4 would be a full quarter, already covered by the existing standard). And, likewise, a hi-res tube would have a two-digit value from 01 to 11.

For the direction, the + and - characters are intuitive enough for this, but '+' in particular is not acceptable so we just need different signifiers. Maybe p and q could work, or to Willy's suggestion of abandoning cryptic codes in favor of descriptive terms, maybe just spell out "plus" and "minus". Maybe h and v are better choices: h means measuring from the horizontal plane of the major radius (think of standing on that plane, you'd be measuring from the "horizon"), and v means measuring from vertical plane of the minor radius (if you're standing in the tube, look up to the "vertex" of the tube and count from there).

We don't need to know if we're counting "up" or "down" from the horizontal plane, since the y-factor determines this. And we don't need to know if we're counting towards or away from the center of the torus, because we already know whether it's an inner or outer torus.

Peter's suggestion of a full re-working of the naming convention is interesting and raises valid points, but I would place it outside the scope of the immediate question, which is how to designate a new set of partial-tube tori. And the question of different terminology to describe the directional measurements is fascinating, but ultimately more academic than instructive when it comes to providing a useful naming convention.

So in summary, I would suggest using Rene's original proposal, except with the rules for the suffix modified as follows:

• 'h' instead of '+', and 'v' instead of '-'
  
• 1-digit (for 16-res) or 2-digit (for 48-res) value for the number of segments of the partial tube
  

The examples from the original image would thus be:

• Green: t08o8000h1
  
• Pink: t08o8000v3
  
• Blue: t04i8000v2
  
• Red: t08o8000v2
  
• Yellow: t08o8000h2