[x3d-public] text size clarification

[Brutzman, Donald (Don) (CIV)]

On 8/19/2019 6:46 AM, Andreas Plesch wrote:
> https://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/text.html#f-Textsizeandspacingfields
> 
> shows how text is sized with the size field.
> 
> The example text does not have any letters which reach below the baseline, such as g,j,p, or y, or underscore _. The figure implies that a spacing of 1 would mean that such letters overlap with the line of text below. But this is in conflict with the assumption that as the default value a spacing of 1 should give a readable display for most content.
> 
> So should the baseline rather be at the level of the underscore _ ?
> Does a size of 1 mean the letter X is ca. 1 unit tall ?
> Or does it mean that _X in combination is ca. 1 unit tall ?
> 
> Here is how dev. x3dom sizes letters. The square is a unit square, centered at the origin:
> https://raw.githack.com/x3dom/x3dom/master/test/regression-suite/test/cases/text/text.html
> 
> -Andreas
> -- 
> Andreas Plesch
> Waltham, MA 02453
Apologies for missing this note 2 months ago (just before flying to Japan for ISO X3D meeting).  Apparently everyone else did too.

Andreas, might you have suggested prose for a spec revision?

Also wondering how X_ITE, view3dscene and FreeWrl handle this.

Also wondering how HTML5.2 handles this.

Now entered as Mantis issue 1265
https://www.web3d.org/member-only/mantis/view.php?id=1265

Nicholas, I seem to recall your addressing font spacing as part of IRVE at some point... and so you have good fortune to be assigned issue responsibility (for how everyone will view 3D text, for approximately forever).  Hope that is OK!  8)

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman