follow-up set

On Tue, 11 May 2004 23:39:44 +0200, "Rune" <run### [at] runevisioncom> wrote:
> > IIRC splines{} are basically content of patch ported to 3.5.
>
> No, they were very much rewritten from scratch I think.

I'm not sure about that. I see similiarities between current splines.cpp and
splines.c of MegaPOV 0.7.

> > Because nobody made it yet ?
>
> I'm curious how the clock values would work for bezier splines. For
> cubic splines the clock values change not just the time dimension but
> also the path of the spline, since it works by adjusting the tangent
> control points (which the user can't control in a cubic spline).
> However, with bezier splines the user controls the tangent control
> points directly, so having the program adjust those to make them fit the
> clock values might seem odd.

For comparison tcb_spline addition I add new parameters as well.
The syntax for it is:

  spline{
    tcb_spline [ tension FLOAT ] [ continuity FLOAT ] [ bias FLOAT ]
    ENTRY
    ENTRY
    ENTRY
    ...
  }

where ENTRY is more

  ENTRY :
    FLOAT
      [ tension FLOAT ] [ continuity FLOAT ] [ bias FLOAT ]
      VECTOR
      [ tension FLOAT ] [ continuity FLOAT ] [ bias FLOAT ]

so you can define tcb (tension, continuity and bias) parameters
1) immediately after spline type which makes default parameters for all
control points,
2) between clock value and vector control point which affects end of segment
finished by this vertex
3) after vector value which affects begining of next segment started by this
vertex

BTW: I forgot to mention sor_spline which duplicates cross section of sor{}.
This patch is already available in MegaPOV 1.0 and described at
http://megapov.inetart.net/manual/expressions.html#sor_spline
http://abx.art.pl/pov/patches/sorspline.php

ABX

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