I wish to make a "tube" which follows along a set of cartesian coordinates
which I input:

{x1,y1,z1},
{x2,y2,z1},
....
{xN,yN,zN}

and the tube radius.

In general, the "tube" does not obey a quadratic polynomial, but it could
easily be represented by a cubic-spline.  I though about making a bunch of
cylinders, but this might introduce texture that shows the granularity of
my step size.

Does anyone have a solution?

Thanks!
Eric

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Eric Brown nous apporta ses lumieres en ce 11/11/2006 10:40:
> I wish to make a "tube" which follows along a set of cartesian coordinates
> which I input:

> {x1,y1,z1},
> {x2,y2,z1},
> ....
> {xN,yN,zN}

> and the tube radius.

> In general, the "tube" does not obey a quadratic polynomial, but it could
> easily be represented by a cubic-spline.  I though about making a bunch of
> cylinders, but this might introduce texture that shows the granularity of
> my step size.

> Does anyone have a solution?

> Thanks!
> Eric


Using a collection of cylinders, it's best to put spheres at the junctions, they 
help to hide the angling.
A sphere_sweep can be a solution. Point format is <x,y,z>,Rad. Be wary that it 
tend to show some artefacts in some cases and can be slow for large sweeps, 
those showing large, broad curves. This is due of the often huge bounding box. 
In that case, splitting the sweep into several sub-sweeps in an union can 
greatly improve performances.

-- 
Alain
-------------------------------------------------
A true friend is someone who reaches for your hand and touches your heart.

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Eric Brown wrote:
> I wish to make a "tube" which follows along a set of cartesian coordinates
> which I input:
> 
> {x1,y1,z1},
> {x2,y2,z1},
> ....
> {xN,yN,zN}
> 
> and the tube radius.
> 
> In general, the "tube" does not obey a quadratic polynomial, but it could
> easily be represented by a cubic-spline.  I though about making a bunch of
> cylinders, but this might introduce texture that shows the granularity of
> my step size.
> 
> Does anyone have a solution?

sphere_sweep as Alain suggested or a mesh made with NURBS or
other splines possibly combined with some Frenet Frame macros.

-- 
Tor Olav
http://subcube.com

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"Eric Brown" <nomail@nomail> wrote:
> I wish to make a "tube" which follows along a set of cartesian coordinates
> which I input:
>
> {x1,y1,z1},
> {x2,y2,z1},
> ....
> {xN,yN,zN}
>
> and the tube radius.
>
> In general, the "tube" does not obey a quadratic polynomial, but it could
> easily be represented by a cubic-spline.  I though about making a bunch of
> cylinders, but this might introduce texture that shows the granularity of
> my step size.
>
> Does anyone have a solution?
>
> Thanks!
> Eric

do you want the segments to "spline" curve or can they be straight?

are the inputs in a file to start with?

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