Re: Slanted Beams thickness

[Mats Bengtsson]

   On 2022-03-25 01:44, Valentin Petzel wrote:

   Subject:
   Slanted Beams thickness
   From:
   Valentin Petzel [1]<valentin@petzel.at>
   Date:
   2022-03-25 01:44

   To:
   [2]lilypond-devel@gnu.org

Hello,

Lilypond handles slanted Beams in a geometrically weird way, that is, the
thickness is not measured as the shortest distance between the opposing sides
of the boundary, but as vertical distance. This results in Beams getting
optically thinner and closer the higher the slope is. But we can very easily
factor this out by adjusting the thickness to the slope. In fact if we want to
achieve a real thickness theta the adjusted thickness would need to be
theta·sqrt(1 + slope²). See attached an experimental example.

Cheers,
Valentin

   A couple of points, on top of what has already been brought up.

   As has already been said, you will hardly notice any difference unless
   the slope is very high, which is a situation that you anyway try to
   avoid as much as possible, which also makes it hard to find examples in
   typeset scores. After all, that's one of the main reasons to use kneed
   beams.

   My gut feeling is that a mathematically exact solution is not likely to
   provide the most pleasing effect to the eye. There are already a number
   of optical corrections applied in LilyPond to handle other such
   discrepancies between the mathematically most obvious solution and the
   visually most pleasing solution. Something in between the current and
   the newly proposed approach is likely to look best.

   Even though a general guiding approach for Lilypond's layout decisions
   is to imitate old hand engraved scores, we shouldn't necessarily copy
   layout decisions that were caused by technical limitations in the hand
   engraving process, if we have a general agreement that something else
   looks better.

      /Mats

References

   1. mailto:valentin@petzel.at
   2. mailto:lilypond-devel@gnu.org