POV-Ray : Newsgroups : povray.general : Request for Comments: Quadratic Bezier Splines : Re: Request for Comments: Quadratic Bezier Splines Server Time
21 Jun 2024 00:17:28 EDT (-0400)
  Re: Request for Comments: Quadratic Bezier Splines  
From: Mr
Date: 8 Jun 2021 04:45:00
Message: <web.60bf2d2584e2d21b16086ed03f378f2@news.povray.org>
clipka <ano### [at] anonymousorg> wrote:
> Hi folks,
> the `prism` primitive currently supports, among others, cubic Bezier
> spline outlines.
> For certain technical reasons, I may need to add support for _quadratic_
> Bezier splines at the render engine level as well, but it would be a
> waste to not expose them to the scene description language (and, while
> I'm at it, possibly also extend `lathe` accordingly).
> An open question is, what keyword should be used for this type of spline?
> For the records:
> - Quadratic Bezier splines are a flavor of quadratic splines, aka 2nd
> order polynomial splines.
> - Quadratic splines are also occasionally referred to as "conic splines"
> or "conic arcs", for reasons I'm not entirely sure of.
> - `bezier_spline` is the current moniker for cubic Bezier splines.
> - `quadratic_spline` is already in use for some quirky flavor of
> quadratic spline that, in my mind, doesn't even deserve to live, but has
> a long-standing tradition of existing under this moniker and therefore
> isn't going anywhere in POV-Ray v3.x.
> Here are some ideas:
> - `quadratic_bezier_spline`, being the most accurate term.
> - `conic_bezier_spline`, being a bit shorter.
> - `conic_spline`, being yet shorter.
> - `bezier2_spline`, the "2" referring to the polynomial order.
> Personally, I'm somewhat unhappy with the very first for being rather
> verbose, and the third for being prone to confusion with both
> `cubic_spline` and `conic_sweep`, the latter being also used in `prism`.
> I'm also not quite happy with the second one, because it's still
> somewhat lengthy, and I think it isn't the most accurate of terms.
> Thoughts, anyone?

Well, Probably the least technical thought ever, but I find names like
something2  something3 rather drafty looking. Even mesh2 doesn't look like the
"goto" syntax it should be; it just makes it look secondary to me. Also because
without any space or underscore makes it look like a backend programer's stuff
not eyepleasing user API level... In many software the  word b_spline
("B-Spline") seems quite conventional to talk about bezier spline if less
verbosity is needed, maybe that could provide inspiration for more options?
Also, sorry if below point even increases the challenge, but to be future proof,
couldn't this be planned with respect to the eventuality of NURBS getting into
POV master one day, avoiding collisions, but also solving the confusion existing
in most other software between these (different? hierarchized?) kinds of

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