POV-Ray : Newsgroups : povray.object-collection : SphereSweep 1.1, with B-splines Server Time: 14 Dec 2018 00:23:37 GMT
  SphereSweep 1.1, with B-splines (Message 1 to 9 of 9)  
From: Cousin Ricky
Subject: SphereSweep 1.1, with B-splines
Date: 28 Aug 2015 23:15:52
Message: <55e0eba8@news.povray.org>
In SphereSweep 1.1, the B-spline has been implemented for the 
sphere_sweep alternatives.  It can now be used with all of the object 
macros, not just with SphereSweep_Native() as in version 1.0.

http://lib.povray.org/searchcollection/index2.php?objectName=SphereSweep&contributorTag=Cousin%20Ricky

I am moving Bézier spline up on the priority list for a future version. 
  However, implementation will not be straightforward, due to the 
possibility of disjointed spline segments.


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From: LanuHum
Subject: Re: SphereSweep 1.1, with B-splines
Date: 29 Aug 2015 07:50:00
Message: <web.55e16403bb12a32f7a3e03fe0@news.povray.org>
Cousin Ricky <ric### [at] yahoocom> wrote:
>
> I am moving Bezier spline up on the priority list for a future version.
>   However, implementation will not be straightforward, due to the
> possibility of disjointed spline segments.

It is interesting! :)


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From: And
Subject: Re: SphereSweep 1.1, with B-splines
Date: 2 Sep 2015 03:50:01
Message: <web.55e670f6bb12a32fffeac2440@news.povray.org>
Cousin Ricky <ric### [at] yahoocom> wrote:
> In SphereSweep 1.1, the B-spline has been implemented for the
> sphere_sweep alternatives.  It can now be used with all of the object
> macros, not just with SphereSweep_Native() as in version 1.0.
>
>
http://lib.povray.org/searchcollection/index2.php?objectName=SphereSweep&contributorTag=Cousin%20Ricky
>
> I am moving Bézier spline up on the priority list for a future version.
>   However, implementation will not be straightforward, due to the
> possibility of disjointed spline segments.


Hello, Cousin Ricky, I'm not sure that you have the plane to make the Bezier
spline sphere sweep macros during the next weeks. Basically I've written one, at
http://news.povray.org/povray.binaries.scene-files/thread/%3Cweb.55d0c6ee48951ba98423d9aa0%40news.povray.org%3E/

And maybe I will write a more general version that put a 'merge' feature and the
variant radius feature on it. We can discuss it.


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From: And
Subject: Re: SphereSweep 1.1, with B-splines
Date: 2 Sep 2015 04:05:01
Message: <web.55e67445bb12a32fffeac2440@news.povray.org>
"LanuHum" <Lan### [at] yandexru> wrote:
> Cousin Ricky <ric### [at] yahoocom> wrote:
> >
> > I am moving Bezier spline up on the priority list for a future version.
> >   However, implementation will not be straightforward, due to the
> > possibility of disjointed spline segments.
>
> It is interesting! :)

Hello, LanuHum.
I'm sorry. I didn't see this message by you:
http://news.povray.org/povray.binaries.scene-files/thread/%3Cweb.55d0c6ee48951ba98423d9aa0%40news.povray.org%3E/

And I've replied it.


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From: LanuHum
Subject: Re: SphereSweep 1.1, with B-splines
Date: 2 Sep 2015 18:35:01
Message: <web.55e740babb12a32f7a3e03fe0@news.povray.org>
"And" <49341109@ntnu.edu.tw> wrote:
> "LanuHum" <Lan### [at] yandexru> wrote:
> > Cousin Ricky <ric### [at] yahoocom> wrote:
> > >
> > > I am moving Bezier spline up on the priority list for a future version.
> > >   However, implementation will not be straightforward, due to the
> > > possibility of disjointed spline segments.
> >
> > It is interesting! :)
>
> Hello, LanuHum.
> I'm sorry. I didn't see this message by you:
>
http://news.povray.org/povray.binaries.scene-files/thread/%3Cweb.55d0c6ee48951ba98423d9aa0%40news.povray.org%3E/
>
> And I've replied it.

I control events. I already included your macro in the exporter. It is good that
it compact and available to understanding. I wait for change of radius along a
curve. :)
If the macro from Cousin Ricky has interesting features, I also want them to
see.:)


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From: And
Subject: Re: SphereSweep 1.1, with B-splines
Date: 3 Sep 2015 04:30:01
Message: <web.55e7ccacbb12a32ff1376bd90@news.povray.org>
"LanuHum" <Lan### [at] yandexru> wrote:
> "And" <49341109@ntnu.edu.tw> wrote:
> > "LanuHum" <Lan### [at] yandexru> wrote:
> > > Cousin Ricky <ric### [at] yahoocom> wrote:
> > > >
> > > > I am moving Bezier spline up on the priority list for a future version.
> > > >   However, implementation will not be straightforward, due to the
> > > > possibility of disjointed spline segments.
> > >
> > > It is interesting! :)
> >
> > Hello, LanuHum.
> > I'm sorry. I didn't see this message by you:
> >
http://news.povray.org/povray.binaries.scene-files/thread/%3Cweb.55d0c6ee48951ba98423d9aa0%40news.povray.org%3E/
> >
> > And I've replied it.
>
> I control events. I already included your macro in the exporter. It is good that
> it compact and available to understanding. I wait for change of radius along a
> curve. :)
> If the macro from Cousin Ricky has interesting features, I also want them to
> see.:)

Well.


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From: Cousin Ricky
Subject: Re: SphereSweep 1.1, with B-splines
Date: 3 Sep 2015 19:05:00
Message: <web.55e89844bb12a32f17f16dc30@news.povray.org>
"And" <49341109@ntnu.edu.tw> wrote:
> Cousin Ricky <ric### [at] yahoocom> wrote:
> >
> > I am moving Bézier spline up on the priority list for a future version.
> >   However, implementation will not be straightforward, due to the
> > possibility of disjointed spline segments.
>
>
> Hello, Cousin Ricky, I'm not sure that you have the plane to make the Bezier
> spline sphere sweep macros during the next weeks. Basically I've written one, at
>
http://news.povray.org/povray.binaries.scene-files/thread/%3Cweb.55d0c6ee48951ba98423d9aa0%40news.povray.org%3E/
>
> And maybe I will write a more general version that put a 'merge' feature and the
> variant radius feature on it. We can discuss it.

I began work on the Bezier sphere sweep last week.  The Bezier calculation macro
is already complete, and accommodates variable radii.  The hard part is to
integrate the Bezier calculation into my existing macros.

I will take a look at your file.  Please be aware that the Object Collection
requires the GNU Lesser General Public License (LGPL) 2.1, so if I end up
borrowing any of your code, you will need to consent to offering that license
before I can upload it.  The LGPL is just about the most generous license out
there, leaving you with little more than token ownership of your intellectual
property, so you'll want to read it very carefully before consenting to offer
it.


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From: And
Subject: Re: SphereSweep 1.1, with B-splines
Date: 5 Sep 2015 14:40:00
Message: <web.55eafdc7bb12a32f57fdff410@news.povray.org>
"Cousin Ricky" <rickysttATyahooDOTcom> wrote:
> "And" <49341109@ntnu.edu.tw> wrote:
> > Cousin Ricky <ric### [at] yahoocom> wrote:
> > >
> > > I am moving Bézier spline up on the priority list for a future version.
> > >   However, implementation will not be straightforward, due to the
> > > possibility of disjointed spline segments.
> >
> >
> > Hello, Cousin Ricky, I'm not sure that you have the plane to make the Bezier
> > spline sphere sweep macros during the next weeks. Basically I've written one, at
> >
http://news.povray.org/povray.binaries.scene-files/thread/%3Cweb.55d0c6ee48951ba98423d9aa0%40news.povray.org%3E/
> >
> > And maybe I will write a more general version that put a 'merge' feature and the
> > variant radius feature on it. We can discuss it.
>
> I began work on the Bezier sphere sweep last week.  The Bezier calculation macro
> is already complete, and accommodates variable radii.  The hard part is to
> integrate the Bezier calculation into my existing macros.
>
> I will take a look at your file.  Please be aware that the Object Collection
> requires the GNU Lesser General Public License (LGPL) 2.1, so if I end up
> borrowing any of your code, you will need to consent to offering that license
> before I can upload it.  The LGPL is just about the most generous license out
> there, leaving you with little more than token ownership of your intellectual
> property, so you'll want to read it very carefully before consenting to offer
> it.

Ok. Thank you very much.

Well, I wondering what the radius formula do others like you apply? I think that
it can be the similar form as the bezier curve in a sense:

r = r0*pow(1-t,3) + r1*pow(1-t,2)*t + r2*(1-t)*pow(t,2) + r3*pow(t,3)
0 <= t <= 1
That is, four points and four radii decide a segment.
Wondering how do you think?


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From: Cousin Ricky
Subject: Re: SphereSweep 1.1, with B-splines
Date: 7 Sep 2015 23:31:18
Message: <55ee1e46$1@news.povray.org>
On 09/05/2015 10:35 AM, And wrote:
> Well, I wondering what the radius formula do others like you apply? I think that
> it can be the similar form as the bezier curve in a sense:
>
> r = r0*pow(1-t,3) + r1*pow(1-t,2)*t + r2*(1-t)*pow(t,2) + r3*pow(t,3)
> 0 <= t <= 1
> That is, four points and four radii decide a segment.
> Wondering how do you think?

I am treating the radii simply as a 4th vector component, just as with 
all the other spline types.  This seems consistent with how POV-Ray 
determines the radii of B-spline and cubic sphere_sweeps.

SphereSweep 1.2 is in testing phase right now.  I had to create a test 
suite just for the Bézier sphere sweep, as the possibility of disjointed 
segments made them trickier to implement than the other spline types.  I 
am still working on the test cases for variable radius sweeps.

As it turns out, I did not need your code, so there is no concern about 
licensing.


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