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> "Nekar Xenos" <nek### [at] gmail com> wrote:
>> On Sun, 27 Apr 2014 18:23:23 +0200, Alain <kua### [at] videotronca> wrote:
>>
>>
>>>> On Fri, 25 Apr 2014 20:07:55 +0200, LanuHum <Lan### [at] yandexru> wrote
>> :
>>>>
>>>>> Me all interests about Povray
>>>>> http://atrey.karlin.mff.cuni.cz/~0rfelyus/
>>>>>
>>>>> RBezier
>>>>> This patch is the last in my series of patches for POV-Ray. It exten
>> ds
>>>>> POV-Ray
>>>>> by ray tracing of trimmed rational Bezier surface patches using Bezi
>> er
>>>>> clipping
>>>>> (as described by Nishita, Sederberg and Kakimoto).
>>>>> ftp://atrey.karlin.mff.cuni.cz/pub/local/0rfelyus/povray-3.02/exampl
>> es/trims-b.png
>>>>>
>>>>>
>>>>> I didn't find in Povray-3.7 opportunity to create bezier patch
>>>>> Good idea for creation of leaves
>>>>
>>>> If I understand correctly this could have helped me when I made my ba
>> ss
>>>> for cutting the c-holes from the sound-box.
>>>>
>>>
>>> An electric bass guitar with a violin/celo body? That's new...
>>
>> My design electro-acoustic bass based on a contra-bass.
>> I hand-coded the sound-box as a bezier patch. I CSG'd the C-holes out of
>>
>>
>> the soundbox but I couldn't add depth because I couldn't csg the sides o
>> f
>>
>> the C-holes. I was thinking maybe this patch would make it possible.
>>
>> --
>>
>> -Nekar Xenos-
>
> What about putting a thin box inside the soundbox behind where the C-holes are
> then simply cutting a hole in this box as well?
>
> Seab
>
The surface is not flat. This mean that the proposed box will either
show some gap or protude from the front face. Both are undesireable.
Alain
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On Mon, 28 Apr 2014 22:43:40 +0200, andrel <byt### [at] gmailcom> wrote:
> On 27-4-2014 22:21, Nekar Xenos wrote:
>> On Sun, 27 Apr 2014 19:25:25 +0200, andrel <byt### [at] gmailcom> wrote:
>>
>>>
>>>>> An electric bass guitar with a violin/celo body? That's new...
>>>>
>>>> My design electro-acoustic bass based on a contra-bass.
>>>> I hand-coded the sound-box as a bezier patch. I CSG'd the C-holes out
>>>> of
>>>> the soundbox but I couldn't add depth because I couldn't csg the sides
>>>> of the C-holes. I was thinking maybe this patch would make it
>>>> possible.
>>>>
>>> Could you not subtract the a scaled down version to create the
>>> resonance chamber?
>>> I am assuming that the thickness of the upper and lower surfaces need
>>> not be detailed modelled to get a realistic sound body.
>>>
>> It just ends up looking like a shadow. I need to do the walls/edges of
>> the c-holes and they need to match.
>>
>
> BTW why the C-holes? I could not find an example of a real instrument
> that has them.
http://www.google.co.za/imgres?imgurl=http%3A%2F%2Fwww.christianlaborie.com%2Fimages%2Fbaroque%2Fcordes%2Fimage-1.jpg&imgrefurl=http%3A%2F%2Fwww.christianlaborie.com%2Fenglish%2Fbaroques.html&h=700&w=465&tbnid=QK-Z8EMVlbgO8M%3A&zoom=1&docid=3DP9e9IG1NQmmM&ei=lVxmU9G1IpCI7AbZ_YHwAQ&tbm=isch&ved=0CFIQMygAMAA&iact=rc&uact=3&dur=784&page=1&start=0&ndsp=35
C-holes are mostly found on viola da gamba. I like the idea of c-holes for
a bass because it somewhat resembles the bass-clef.
> Mechanically they make also less sense as far as I understand the
> physics behind the violin family.
> And who is G Oosthuizen?
>
My real name is Gerhard Oosthuizen :)
--
-Nekar Xenos-
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On 4-5-2014 17:39, Nekar Xenos wrote:
> On Mon, 28 Apr 2014 22:43:40 +0200, andrel <byt### [at] gmailcom> wrote:
>
>> BTW why the C-holes? I could not find an example of a real instrument
>> that has them.
>
>
http://www.google.co.za/imgres?imgurl=http%3A%2F%2Fwww.christianlaborie.com%2Fimages%2Fbaroque%2Fcordes%2Fimage-1.jpg&imgrefurl=http%3A%2F%2Fwww.christianlaborie.com%2Fenglish%2Fbaroques.html&h=700&w=465&tbnid=QK-Z8EMVlbgO8M%3A&zoom=1&docid=3DP9e9IG1NQmmM&ei=lVxmU9G1IpCI7AbZ_YHwAQ&tbm=isch&ved=0CFIQMygAMAA&iact=rc&uact=3&dur=784&page=1&start=0&ndsp=35
ok, did not find that one
>
> C-holes are mostly found on viola da gamba. I like the idea of c-holes
> for a bass because it somewhat resembles the bass-clef.
I assumed so
>> Mechanically they make also less sense as far as I understand the
>> physics behind the violin family.
Still don't see the point from a physics point of view. ;)
>> And who is G Oosthuizen?
>>
> My real name is Gerhard Oosthuizen :)
I should have guessed from your nickname
Strange mix of dutch lastname and german firstname.
--
Everytime the IT department forbids something that a researcher deems
necessary for her work there will be another hole in the firewall.
---
This email is free from viruses and malware because avast! Antivirus protection is
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What is C-holes?
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On 4-5-2014 21:58, LanuHum wrote:
> What is C-holes?
Violins, cellos and other members of the violin family have slots cut
out in the top plate. These follow more or less the curve of the wall at
the height of the bridge. They are more ornamented than simple lines
with round holes at the ends and a thickening in the middle. Giving them
(at least the left one) more or less the shape of a script 'f'. Hence
these are called f-holes.
https://en.wikipedia.org/wiki/File:Violinconsruction3.JPG
Apparently older violins/violins da gamba sometimes had c shaped holes.
Actually you can find one on the wikipedia page of the violin
https://en.wikipedia.org/wiki/Violin
Here they are in the middle of the waist, where it makes sense. The
image Nekar Xenos referred to was a bit odd in my opinion.
More background: the way sound is generated by a violin is a bit more
complicated than you might think and is different for high and low
frequencies. Key components are the Bridge, the sound post that connects
the top en back plate, more or less under one of the feet of the bridge,
and the back plate that is thickest precisely where the sound post
stands, and the fact that the bow make the strings vibrate in such a way
that the bridge wiggles.
The back plate has a low resonance frequency and the top plate a higher
frequency. For higher frequencies the major contribution comes from the
top plate where the left part moves more up and down than the right
half. Lower frequencies are carried by the entire back plate. And then
we have the resonance chamber.
In short: a violin is not a symmetric instrument at all. If it would be,
it would almost produce no sound at all.
If I remember correctly, the f-holes in the cello leave two pieces of
wood on 'peninsulas' that according to a friend of mine (who builds
string instruments) are responsible for wolf tones.
--
Everytime the IT department forbids something that a researcher deems
necessary for her work there will be another hole in the firewall.
---
This email is free from viruses and malware because avast! Antivirus protection is
active.
http://www.avast.com
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On Sun, 04 May 2014 18:53:34 +0200, andrel <byt### [at] gmailcom> wrote:
> On 4-5-2014 17:39, Nekar Xenos wrote:
>> On Mon, 28 Apr 2014 22:43:40 +0200, andrel <byt### [at] gmailcom> wrote:
>>
>
>>> BTW why the C-holes? I could not find an example of a real instrument
>>> that has them.
>>
>>
http://www.google.co.za/imgres?imgurl=http%3A%2F%2Fwww.christianlaborie.com%2Fimages%2Fbaroque%2Fcordes%2Fimage-1.jpg&imgrefurl=http%3A%2F%2Fwww.christianlaborie.com%2Fenglish%2Fbaroques.html&h=700&w=465&tbnid=QK-Z8EMVlbgO8M%3A&zoom=1&docid=3DP9e9IG1NQmmM&ei=lVxmU9G1IpCI7AbZ_YHwAQ&tbm=isch&ved=0CFIQMygAMAA&iact=rc&uact=3&dur=784&page=1&start=0&ndsp=35
>
> ok, did not find that one
>
>>
>> C-holes are mostly found on viola da gamba. I like the idea of c-holes
>> for a bass because it somewhat resembles the bass-clef.
>
> I assumed so
>
>>> Mechanically they make also less sense as far as I understand the
>>> physics behind the violin family.
>
> Still don't see the point from a physics point of view. ;)
>
>>> And who is G Oosthuizen?
>>>
>> My real name is Gerhard Oosthuizen :)
>
> I should have guessed from your nickname
>
> Strange mix of dutch lastname and german firstname.
>
Gerhard Oosthuizen is a very common name here in South Africa.
--
-Nekar Xenos-
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On Sun, 04 May 2014 23:25:04 +0200, andrel <byt### [at] gmailcom> wrote:
> On 4-5-2014 21:58, LanuHum wrote:
>> What is C-holes?
>
> Violins, cellos and other members of the violin family have slots cut
> out in the top plate. These follow more or less the curve of the wall at
> the height of the bridge. They are more ornamented than simple lines
> with round holes at the ends and a thickening in the middle. Giving them
> (at least the left one) more or less the shape of a script 'f'. Hence
> these are called f-holes.
> https://en.wikipedia.org/wiki/File:Violinconsruction3.JPG
>
> Apparently older violins/violins da gamba sometimes had c shaped holes.
> Actually you can find one on the wikipedia page of the violin
> https://en.wikipedia.org/wiki/Violin
> Here they are in the middle of the waist, where it makes sense. The
> image Nekar Xenos referred to was a bit odd in my opinion.
>
> More background: the way sound is generated by a violin is a bit more
> complicated than you might think and is different for high and low
> frequencies. Key components are the Bridge, the sound post that connects
> the top en back plate, more or less under one of the feet of the bridge,
> and the back plate that is thickest precisely where the sound post
> stands, and the fact that the bow make the strings vibrate in such a way
> that the bridge wiggles.
> The back plate has a low resonance frequency and the top plate a higher
> frequency. For higher frequencies the major contribution comes from the
> top plate where the left part moves more up and down than the right
> half. Lower frequencies are carried by the entire back plate. And then
> we have the resonance chamber.
> In short: a violin is not a symmetric instrument at all. If it would be,
> it would almost produce no sound at all.
>
> If I remember correctly, the f-holes in the cello leave two pieces of
> wood on 'peninsulas' that according to a friend of mine (who builds
> string instruments) are responsible for wolf tones.
>
I wonder how much your friend would charge to build this bass :)
--
-Nekar Xenos-
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