Hi,

	I wanted to create an object (bottle, in this case) that has rotational 
symmetry about an axis. So an SOR or Lathe seemed like good choices.

	Consider a bottle. It's base is flat, but the edges of the base are 
rounded and then go up vertically. As I wanted the roundness, I chose 
not to use linear interpolation, and tried some of the other types.

	Getting it rounded was not much of a problem, but then I could not get 
the "line" to go up vertically. To give you an idea as to what I mean, I 
wanted the base to be of radius about 1. So I picked my base points at 
(0,0), (0.95,0).

	Then I had a few points to curve it upwards. Let's say I ended up at 
(1,0.05). Now I just want to go vertically up to about (1,4). How do I 
do it? If I just put one point, it curves. I thought I could put a 
number of intermediate points (1,1), (1,1.5), and so on, but that didn't 
achieve the desired effect.

	In the end, I used a superellipsoid, with some CSG (better solution). 
However, for future reference, is there any way I can get a vertically 
edge using anything other than linear interpolation?

	In general, are there any tricks to dealing with rounded edges or 
corners? A while ago I was trying to make a cube, but with rounded edges 
and corners. The edges can be done with CSG, but it was somewhat of a 
pain and the corners didn't work out...

Thanks,
-- 
Aim Low, Reach Your Goals, Avoid Disappointment.


                     /\  /\               /\  /
                    /  \/  \ u e e n     /  \/  a w a z
                        >>>>>>m.n### [at] ieeeorg<<<<<<
                                    anl

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"Mueen Nawaz" <m.n### [at] ieeeorg> wrote in message 
news:41b64dfe$1@news.povray.org...
>
> Consider a bottle. It's base is flat, but the edges of the base are 
> rounded and then go up vertically. Getting it rounded was not much of a 
> problem, but then I could not get the "line" to go up vertically.

Try a bezier_spline, as in:

lathe {
  bezier_spline // four points per segment
  8,
  <0, 0>, <0.95, 0>, <1, 0.05>, <1, 0.1>
  <1, 0.1>, <1, 2>, <1, 3>, <1, 4>
}

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On Tue, 07 Dec 2004 18:42:12 -0600, Mueen Nawaz <m.n### [at] ieeeorg> wrote:
> In general, are there any tricks to dealing with rounded edges or 
> corners?

Do a cross section of the glass using spline and then "rotate" it as:
mesh using Ingo's macros ( http://members.home.nl/seedseven/#lathe ) or
isosurface using IsoCSG (
http://www-public.tu-bs.de/~y0013390/pov/ic/docu02.html#Shaped_Torus )
Both are pretty well documented. In case of isosurface you need to make a
function over one component of given spline.

ABX

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