POV-Ray : Newsgroups : povray.general : NURBS support ? Server Time
16 Nov 2024 05:17:21 EST (-0500)
  NURBS support ? (Message 1 to 8 of 8)  
From: Stefan Betermieux
Subject: NURBS support ?
Date: 19 Oct 1998 09:19:15
Message: <362B2E42.40F8A97B@fernuni-hagen.de>
Hi !

Are there any plans to implement a basic NURBS support into the Povray
scene description language ? I am using a NURBS modeller and it is a
real mess to convert everything to meshes. The file sizes and parse
times grow incredible. I have seen the bezier functionality in Povray,
perhaps someone who knows the math stuff can write a converter which
translates NURBS into b-splines and b-patches.

I am currently using Rhino 3D, which supports the NURBS standard file
format IGES.

bye,
Stefan


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From: Ken
Subject: Re: NURBS support ?
Date: 19 Oct 1998 11:57:19
Message: <362B5329.3D902979@pacbell.net>
Stefan Betermieux wrote:

> Hi !
>
> Are there any plans to implement a basic NURBS support into the Povray
> scene description language ? I am using a NURBS modeller and it is a
> real mess to convert everything to meshes. The file sizes and parse
> times grow incredible. I have seen the bezier functionality in Povray,
> perhaps someone who knows the math stuff can write a converter which
> translates NURBS into b-splines and b-patches.
>
> I am currently using Rhino 3D, which supports the NURBS standard file
> format IGES.
>
> bye,
> Stefan



Greetings !

   I haven't heard of anything about adding Nurbs support any time
in the near future but that doesn't mean it hasn't been talked about
and won't happen. I know what you mean about large triangle bearing
files. They are cumbersome to say the least and lack editability.

   Fortunately there has been a new program written that you might
want to investigate. Developed by Warp, and currently is supported
by Chris Colefax, it is said to be able to dramatically reduce the
overall number of triangles used in a mesh object without any
noticeable loss of model resolution.
   You can find the program available for free and ready for
download at the "Chris Colefax Incredible Include Files" web site.

http://www.geocities.com/SiliconValley/Lakes/1434/

Ken Tyler


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From: Ron Parker
Subject: Re: NURBS support ?
Date: 19 Oct 1998 13:01:16
Message: <362b624c.0@news.povray.org>
On Mon, 19 Oct 1998 07:56:41 -0700, Ken <tyl### [at] pacbellnet> wrote:
>Stefan Betermieux wrote:
>
>> Hi !
>>
>> Are there any plans to implement a basic NURBS support into the Povray
>> scene description language ? I am using a NURBS modeller and it is a
>> real mess to convert everything to meshes. The file sizes and parse
>> times grow incredible. I have seen the bezier functionality in Povray,
>> perhaps someone who knows the math stuff can write a converter which
>> translates NURBS into b-splines and b-patches.
>>
>> I am currently using Rhino 3D, which supports the NURBS standard file
>> format IGES.
>
>   I haven't heard of anything about adding Nurbs support any time
>in the near future but that doesn't mean it hasn't been talked about
>and won't happen. I know what you mean about large triangle bearing
>files. They are cumbersome to say the least and lack editability.

NURBS are not much more likely to be 'editable.'  At least, not by
my definition of editable.  Nevertheless, there is at least one 
effort underway to add NURBS to POV-Ray, at least as an unofficial
patch.  Converting from an industry-standard format to whatever 
develops for POV will probably end up being an additional project, 
however.


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From: Johannes Hubert
Subject: Re: NURBS support ?
Date: 20 Oct 1998 12:24:30
Message: <362cab2e.0@news.povray.org>
Not withstanding that it is possible to reduce the triangle count in meshes,
this is not what happens in the tool/INC developed by Warp and Chris (at
least not as I understand it):
Warp's tool does not reduce the triangle count of the mesh, but it only
saves the triangles in a much more compact format, so that the filesize for
saving them is about 20%-30%. Chris' INC then takes advantage of POV 3.1's
file commands to read this compact format and re-create the mesh in POV-Ray:
The mesh-object in POV-Ray is just the same, only the file to save the
meshes is much smaller.
Am I wrong here?

Johannes.



Ken wrote in message <362B5329.3D902979@pacbell.net>...
>Stefan Betermieux wrote:
>
>> Hi !
>>
>> Are there any plans to implement a basic NURBS support into the Povray
>> scene description language ? I am using a NURBS modeller and it is a
>> real mess to convert everything to meshes. The file sizes and parse
>> times grow incredible. I have seen the bezier functionality in Povray,
>> perhaps someone who knows the math stuff can write a converter which
>> translates NURBS into b-splines and b-patches.
>>
>> I am currently using Rhino 3D, which supports the NURBS standard file
>> format IGES.
>>
>> bye,
>> Stefan
>
>
>
>Greetings !
>
>   I haven't heard of anything about adding Nurbs support any time
>in the near future but that doesn't mean it hasn't been talked about
>and won't happen. I know what you mean about large triangle bearing
>files. They are cumbersome to say the least and lack editability.
>
>   Fortunately there has been a new program written that you might
>want to investigate. Developed by Warp, and currently is supported
>by Chris Colefax, it is said to be able to dramatically reduce the
>overall number of triangles used in a mesh object without any
>noticeable loss of model resolution.
>   You can find the program available for free and ready for
>download at the "Chris Colefax Incredible Include Files" web site.
>
>http://www.geocities.com/SiliconValley/Lakes/1434/
>
>Ken Tyler
>


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From: Nieminen Mika
Subject: Re: NURBS support ?
Date: 20 Oct 1998 15:16:31
Message: <362cd37f.0@news.povray.org>
Johannes Hubert <jhu### [at] algonetse> wrote:
: Warp's tool does not reduce the triangle count of the mesh, but it only
: saves the triangles in a much more compact format, so that the filesize for
: saving them is about 20%-30%. Chris' INC then takes advantage of POV 3.1's
: file commands to read this compact format and re-create the mesh in POV-Ray:
: The mesh-object in POV-Ray is just the same, only the file to save the
: meshes is much smaller.

  You are right.

-- 
                                                           - Warp. -


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From: Stefan Betermieux
Subject: Re: NURBS support ?
Date: 23 Oct 1998 05:39:50
Message: <363040D5.555F23B3@fernuni-hagen.de>
Ron Parker wrote:

> NURBS are not much more likely to be 'editable.'  At least, not by
> my definition of editable.  Nevertheless, there is at least one
> effort underway to add NURBS to POV-Ray, at least as an unofficial
> patch.  Converting from an industry-standard format to whatever
> develops for POV will probably end up being an additional project,
> however.

As you seem to have more information then I, perhaps you can tell me who is
working on the patch. I will be concerned a lot with NURBS in the next
months and perhaps I can contribute this project. Just writing a converter
would end up in the same big files, so I am interested in adding new
keywords to POV. OK, perhaps it is more difficult then I think it is, so any
comments are welcome.

bye
Stefan


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From: Ron Parker
Subject: Re: NURBS support ?
Date: 23 Oct 1998 10:11:48
Message: <36308094.0@news.povray.org>
On Fri, 23 Oct 1998 10:39:49 +0200, Stefan Betermieux 
	<ste### [at] fernuni-hagende> wrote:
>Ron Parker wrote:
>
>> NURBS are not much more likely to be 'editable.'  At least, not by
>> my definition of editable.  Nevertheless, there is at least one
>> effort underway to add NURBS to POV-Ray, at least as an unofficial
>> patch.  Converting from an industry-standard format to whatever
>> develops for POV will probably end up being an additional project,
>> however.
>
>As you seem to have more information then I, perhaps you can tell me who is
>working on the patch. I will be concerned a lot with NURBS in the next
>months and perhaps I can contribute this project. Just writing a converter
>would end up in the same big files, so I am interested in adding new
>keywords to POV. OK, perhaps it is more difficult then I think it is, so any
>comments are welcome.

The only thing I know about the effort is from an offhand comment on a web
page and some commented out source code, so I'm not much of an information
source.  Nathan Kopp is working on the patch, but I don't know the status 
of it.  He reads this group; perhaps he can give you more information.


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From: Nathan Kopp
Subject: Re: NURBS support ?
Date: 25 Oct 1998 00:57:00
Message: <3632A125.F8B30A72@Kopp.com>
Yes... I was working on some NURBS stuff... mostly just playing around...
and it mostly worked but had a few bugs.  Plus it was really slow.  I had
some code that tesselated a non-trimmed NURB surface into a mesh of
triangles, stored internally in POV as a triangle mesh.  It was simply a
new parsing function that was kind of a "front-end" to the POV's existing
triangle mesh object.  I currently don't have time to continue the project,
but if you want to look at my work, send me an email.

-Nathan Kopp
 To send me email, remove the '0' in my email address.

Ron Parker wrote:
> 
> On Fri, 23 Oct 1998 10:39:49 +0200, Stefan Betermieux
>         <ste### [at] fernuni-hagende> wrote:
>
> >As you seem to have more information then I, perhaps you can tell me who is
> >working on the patch. I will be concerned a lot with NURBS in the next
> >months and perhaps I can contribute this project. Just writing a converter
> >would end up in the same big files, so I am interested in adding new
> >keywords to POV. OK, perhaps it is more difficult then I think it is, so any
> >comments are welcome.
> 
> The only thing I know about the effort is from an offhand comment on a web
> page and some commented out source code, so I'm not much of an information
> source.  Nathan Kopp is working on the patch, but I don't know the status
> of it.  He reads this group; perhaps he can give you more information.


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