Todd Taylor wrote:

> "Tor Olav Kristensen" <tto### [at] onlineno> wrote in message
> news:39BD88B9.A8295B7D@online.no...
> <snip>
> > I'm wondering what you mean by this.
> >
> > Does your bowl like object look anything like
> > the vase I just posted to povray.binaries.images ?
> > news://news.povray.org/39BD872A.9D0EE76%40online.no
>
> To tell the truth, I am not altogether sure. :)
>
> > In that image I have used 5 lathes segments to join
> > the 5 prism parts smoothly.
> > (A macro takes care of all the needed calculations.
>
> If I understand you correctly, Tor, you had 5 prism parts and then used 5
> lathe segments to smoothly join the prism parts.  What I am intending to do
> is to take a single prism object and sweep it around an axis, forming
> something akin to a bowl.
>
> For instance, if you were to take the upper case letter "L" and
> rotate it about an axis that ran just even with the end of the
> horizontal "stick" of the "L", you'd have something looking like
> a short, open-ended cylinder.

Are you sure that you can not use an ordinary lathe object
for making such a shape ?

Below are some code that shows how to do this.
I also modified your code a little bit to show how a
bowl can be made with a "rotated" L-shaped prism.

If neither of the two shapes are what you seek, then
please try to explain more. :)


> I want to do the same thing, but with a prism of my own design.
>
> (BTW, your creation, Tor, looks like it'd be good rosebud.  I'd
> be interested on how you did that as well as any ideas you might
> have on this problem as well.  TIA.)

I'll post the code for my "rosebud" later (when I have un-messed it :)


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

// ===== 1 ======= 2 ======= 3 ======= 4 ======= 5 ======= 6 ======= 7

#version 3.1;
#include "colors.inc"

// ===== 1 ======= 2 ======= 3 ======= 4 ======= 5 ======= 6 ======= 7

#declare MyPrism =
prism {
  cubic_spline
  0,
  1,
  9,
  <1,-3>,
  <1,-2>, <7,-2>, <7, 6>, <8, 6>, <8,-3>, <1,-3>, <1,-2>
  <7,-2>
}
// Note that all the first co-ordinates for the points
// above are positive.  That is not required here,
// but it makes it easier to imagine how the "spun"
// object will look like.


#declare NrOfPrisms = 36;

#declare PrismBowl =
union {
  #declare Count = 0;
  #while(Count < NrOfPrisms)
    object { MyPrism rotate 360/NrOfPrisms*Count*z }
    #declare Count = Count + 1;
  #end
  rotate -90*x
}


#declare LatheBowl =
lathe {
  cubic_spline
  9,
  <1,-3>,
  <1,-2>, <7,-2>, <7, 6>, <8, 6>, <8,-3>, <1,-3>, <1,-2>
  <7,-2>
}
// Note that the first and last point in the middle line
// are equal.
// Also note that the point in the first line is equal
// to the second last point in the middle line.
// And that the point in the last line is equal to
// the second point in the middle line.
// (This makes a "smooth" and "closed" cubic_spline)


object {
  PrismBowl
  pigment { Green }
  translate -10*x
}


object {
  LatheBowl
  pigment { Red }
  translate 10*x
}

// ===== 1 ======= 2 ======= 3 ======= 4 ======= 5 ======= 6 ======= 7

background { color White }

light_source { 100*<1, 5, -2> color White }

camera {
  location <0, 5, -3>*7
  look_at <0, 0, 0>
}

// ===== 1 ======= 2 ======= 3 ======= 4 ======= 5 ======= 6 ======= 7

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