POV-Ray : Newsgroups : povray.newusers : Polygon Sweeps Server Time
5 Nov 2024 07:18:46 EST (-0500)
  Polygon Sweeps (Message 1 to 7 of 7)  
From: bongotastic
Subject: Polygon Sweeps
Date: 23 Feb 2004 13:54:26
Message: <403a4c62@news.povray.org>
Hi all,

    Is there a way to do simple polygon/spline sweep rather than sphere
sweep? By this, I mean sweeping a 2D object along a 3D spline. I feel like
it should be there but I did not see this in the docs.

    Thanks


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From: Christopher James Huff
Subject: Re: Polygon Sweeps
Date: 23 Feb 2004 21:35:41
Message: <cjameshuff-47EE6F.21362623022004@news.povray.org>
In article <403a4c62@news.povray.org>,
 "bongotastic" <cbl### [at] csdalca> wrote:

>     Is there a way to do simple polygon/spline sweep rather than sphere
> sweep? By this, I mean sweeping a 2D object along a 3D spline. I feel like
> it should be there but I did not see this in the docs.

There is no built in primitive that does this. However, you can do it by 
using the scripting language to build an appropriate mesh, and someone 
may have done an include file for this already.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


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From: Marc Roth
Subject: Re: Polygon Sweeps
Date: 24 Feb 2004 05:41:57
Message: <403b2a75$1@news.povray.org>
bongotastic wrote:
> Hi all,
> 
>     Is there a way to do simple polygon/spline sweep rather than sphere
> sweep? By this, I mean sweeping a 2D object along a 3D spline. I feel like
> it should be there but I did not see this in the docs.
> 
>     Thanks
you could create two splines, one for the position and the other one for 
rotation and simply create many instances of your mesh along the spline. 
the problem is that you need an awful lot of objects to make it look 
smooth. i did this a while ago to make something like a woven piece of 
cloth and it had about 5k objects just for one strand of wool, so it's a 
rather ineffective way...
bye,
	Marc


-- 
---------------------------------
and god said: let there be a light_source { location SUN look_at EARTH, 
rgb SUNLIGHT }


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From: Mike Williams
Subject: Re: Polygon Sweeps
Date: 24 Feb 2004 14:12:03
Message: <a3Z+xHAc35OAFw6c@econym.demon.co.uk>
Wasn't it Christopher James Huff who wrote:
>In article <403a4c62@news.povray.org>,
> "bongotastic" <cbl### [at] csdalca> wrote:
>
>>     Is there a way to do simple polygon/spline sweep rather than sphere
>> sweep? By this, I mean sweeping a 2D object along a 3D spline. I feel like
>> it should be there but I did not see this in the docs.
>
>There is no built in primitive that does this. However, you can do it by 
>using the scripting language to build an appropriate mesh, and someone 
>may have done an include file for this already.

Now that the web interface to news is back up, I can tell you that you
can get my SweepSpline macro which does that from

http://news.povray.org/povray.binaries.scene-files/thread/%3C3fb73d9e%40news.povray.org%3E/

(The trick for finding the message-id, and thereby writing more direct
and shorter URLs seems to not be present any more, so you'll have to
make do with this long threadwise URL.)

For a polygon to work properly, you should make it a linear_spline and 
ensure that its control points take values that are multiples of 
1/Vpoints. E.g. if you tell the mesh to use 20 points around the 
circumference, then you can set your control points to multiples
of 0.05

-- 
Mike Williams
Gentleman of Leisure


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From: Ken
Subject: Re: Polygon Sweeps
Date: 24 Feb 2004 22:05:29
Message: <403C119C.F3B06CBF@tag.povray.org>
Mike Williams wrote:


>
http://news.povray.org/povray.binaries.scene-files/thread/%3C3fb73d9e%40news.povray.org%3E/
> 
> (The trick for finding the message-id, and thereby writing more direct
> and shorter URLs seems to not be present any more, so you'll have to
> make do with this long threadwise URL.)

Use - http://tinyurl.com/

This -

http://news.povray.org/povray.binaries.scene-files/thread/%3C3fb73d9e%40news.povray.org%3E/

Becomes this -

http://tinyurl.com/2u4ox

-- 
Ken Tyler


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From: bongotastic
Subject: Re: Polygon Sweeps
Date: 25 Feb 2004 10:32:40
Message: <403cc018$1@news.povray.org>
Thanks, I will try this later on today.

bongo


"Mike Williams" <nos### [at] econymdemoncouk> wrote in message
news:a3Z+xHA### [at] econymdemoncouk...
> Wasn't it Christopher James Huff who wrote:
> >In article <403a4c62@news.povray.org>,
> > "bongotastic" <cbl### [at] csdalca> wrote:
> >
> >>     Is there a way to do simple polygon/spline sweep rather than sphere
> >> sweep? By this, I mean sweeping a 2D object along a 3D spline. I feel
like
> >> it should be there but I did not see this in the docs.
> >
> >There is no built in primitive that does this. However, you can do it by
> >using the scripting language to build an appropriate mesh, and someone
> >may have done an include file for this already.
>
> Now that the web interface to news is back up, I can tell you that you
> can get my SweepSpline macro which does that from
>
>
http://news.povray.org/povray.binaries.scene-files/thread/%3C3fb73d9e%40news.povray.org%3E/
>
> (The trick for finding the message-id, and thereby writing more direct
> and shorter URLs seems to not be present any more, so you'll have to
> make do with this long threadwise URL.)
>
> For a polygon to work properly, you should make it a linear_spline and
> ensure that its control points take values that are multiples of
> 1/Vpoints. E.g. if you tell the mesh to use 20 points around the
> circumference, then you can set your control points to multiples
> of 0.05
>
> -- 
> Mike Williams
> Gentleman of Leisure


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From: Thorsten Froehlich
Subject: Re: Polygon Sweeps
Date: 25 Feb 2004 10:56:16
Message: <403cc5a0$1@news.povray.org>
In article <a3Z+xHA### [at] econymdemoncouk> , Mike Williams 
<nos### [at] econymdemoncouk>  wrote:

>
>
http://news.povray.org/povray.binaries.scene-files/thread/%3C3fb73d9e%40news
.povray.o
> rg%3E/
>
> (The trick for finding the message-id, and thereby writing more direct

It will be back in a few days.

> and shorter URLs seems to not be present any more, so you'll have to
> make do with this long threadwise URL.)

<http://news.povray.org/*/thread/%3C3fb73d9e%40news.povray.org%3E/>

or for the message

<http://news.povray.org/%3C3fb73d9e%40news.povray.org%3E>

will also work.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org


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