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Thought I'd share this with you all.
IMNSHO it's the best rendering of (part of) the Barth Decic that I've seen
for a while.
For the record:
#declare a=1.0
#declare GM=(sqr(5)+1)/2
#declare GM4=pow(GM, 4)
function(x,y,z,a) {
8*(pow(x, 2)-GM4*pow(y, 2))*(pow(y, 2)-GM4*pow(z, 2))*(pow(z, 2)-
GM4*pow(x, 2))*(pow(x, 4)+pow(y, 4)+pow(z, 4)-2*pow(x, 2)*
pow(y, 2)-2*pow(x, 2)*pow(z, 2)-2*pow(y, 2)*pow(z, 2))+(3+5*GM)
*pow((pow(x, 2)+pow(y, 2)+pow(z, 2)-pow(a, 2)),2)*pow((pow(x, 2)
+pow(y, 2)+pow(z, 2)-(2-GM)*pow(a, 2)),2)*pow(a, 2)
}
max_gradient 25060
contained_by{sphere {0, 1.9}}
...and the texture:
texture {
pigment {
aoi <3, 1, 3>
color_map {
[0 color rgb <1.0,0.4,0.25>]
[0.8 color rgb <0.15,0.25,0.9>]
}
}
finish {
ambient 0
diffuse 0.7
specular 0.16
}
}
Must be rendered using Megapov >=1.1
John
--
Run Fast
Run Free
Run Linux
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Attachments:
Download 'Decic.jpg' (82 KB)
Preview of image 'Decic.jpg'
![Decic.jpg](/povray.binaries.images/attachment/%3C433be36c%40news.povray.org%3E/Decic.jpg?ttop=441697&toff=4900&preview=1)
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Doctor John wrote:
> Thought I'd share this with you all.
> IMNSHO it's the best rendering of (part of) the Barth Decic that I've seen
> for a while.
>
> For the record:
> #declare a=1.0
> #declare GM=(sqr(5)+1)/2
> #declare GM4=pow(GM, 4)
>
> function(x,y,z,a) {
> 8*(pow(x, 2)-GM4*pow(y, 2))*(pow(y, 2)-GM4*pow(z, 2))*(pow(z, 2)-
> GM4*pow(x, 2))*(pow(x, 4)+pow(y, 4)+pow(z, 4)-2*pow(x, 2)*
> pow(y, 2)-2*pow(x, 2)*pow(z, 2)-2*pow(y, 2)*pow(z, 2))+(3+5*GM)
> *pow((pow(x, 2)+pow(y, 2)+pow(z, 2)-pow(a, 2)),2)*pow((pow(x, 2)
> +pow(y, 2)+pow(z, 2)-(2-GM)*pow(a, 2)),2)*pow(a, 2)
> }
>
> max_gradient 25060
> contained_by{sphere {0, 1.9}}
>
>
> ...and the texture:
> texture {
> pigment {
> aoi <3, 1, 3>
> color_map {
> [0 color rgb <1.0,0.4,0.25>]
> [0.8 color rgb <0.15,0.25,0.9>]
> }
> }
> finish {
> ambient 0
> diffuse 0.7
> specular 0.16
> }
> }
>
> Must be rendered using Megapov >=1.1
>
> John
>
Spiny...
On another note... Anybody: Is there a way to duplicate the aoi pattern
w/ the official POV-Ray?
--
~Mike
Things! Billions of them!
Post a reply to this message
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"Mike Raiford" <mra### [at] hotmail com> wrote in message
news:433be6a8$1@news.povray.org...
>
> Spiny...
>
> On another note... Anybody: Is there a way to duplicate the aoi pattern w/
> the official POV-Ray?
>
Tough, Mike, you gotta get Megapov. It's not difficult to install.
hop over to http://megapov.inetart.net/ and away you go...
btw - make sure you get the latest version (1.2.1 at time of writing)
John
--
Run Fast
Run Free
Run Linux
Post a reply to this message
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Doctor John wrote:
> "Mike Raiford" <mra### [at] hotmail com> wrote in message
> news:433be6a8$1@news.povray.org...
>> Spiny...
>>
>> On another note... Anybody: Is there a way to duplicate the aoi pattern w/
>> the official POV-Ray?
>>
> Tough, Mike, you gotta get Megapov. It's not difficult to install.
> hop over to http://megapov.inetart.net/ and away you go...
> btw - make sure you get the latest version (1.2.1 at time of writing)
>
> John
I have MegaPOV, I'm just looking for an alternative.
--
~Mike
Things! Billions of them!
Post a reply to this message
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> On another note... Anybody: Is there a way to duplicate the aoi pattern
> w/ the official POV-Ray?
You can fake it with the slope pattern if you're only going to see the
object from one direction (no reflections).
- Slime
[ http://www.slimeland.com/ ]
Post a reply to this message
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Slime wrote:
>> On another note... Anybody: Is there a way to duplicate the aoi
>> pattern w/ the official POV-Ray?
>
> You can fake it with the slope pattern if you're only going to see the
> object from one direction (no reflections).
This works best with small camera angles though. Technically it only works
perfectly with an orthographic camera.
Rune
--
3D images and anims, include files, tutorials and more:
rune|vision: http://runevision.com
POV-Ray Ring: http://webring.povray.co.uk
Post a reply to this message
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Doctor John schreef:
> Thought I'd share this with you all.
> IMNSHO it's the best rendering of (part of) the Barth Decic that I've seen
> for a while.
>
> For the record:
> #declare a=1.0
> #declare GM=(sqr(5)+1)/2
> #declare GM4=pow(GM, 4)
>
> function(x,y,z,a) {
> 8*(pow(x, 2)-GM4*pow(y, 2))*(pow(y, 2)-GM4*pow(z, 2))*(pow(z, 2)-
> GM4*pow(x, 2))*(pow(x, 4)+pow(y, 4)+pow(z, 4)-2*pow(x, 2)*
> pow(y, 2)-2*pow(x, 2)*pow(z, 2)-2*pow(y, 2)*pow(z, 2))+(3+5*GM)
> *pow((pow(x, 2)+pow(y, 2)+pow(z, 2)-pow(a, 2)),2)*pow((pow(x, 2)
> +pow(y, 2)+pow(z, 2)-(2-GM)*pow(a, 2)),2)*pow(a, 2)
> }
>
> max_gradient 25060
> contained_by{sphere {0, 1.9}}
>
>
> ...and the texture:
> texture {
> pigment {
> aoi <3, 1, 3>
> color_map {
> [0 color rgb <1.0,0.4,0.25>]
> [0.8 color rgb <0.15,0.25,0.9>]
> }
> }
> finish {
> ambient 0
> diffuse 0.7
> specular 0.16
> }
> }
>
> Must be rendered using Megapov >=1.1
>
> John
Barth's SEXTIC is a surface with 65 double points. It's interesting to
know that 20 of these double points are the vertices of a regular
dodecahedron and 30 other double points are the midpoints of the edges
of another regular dodecahedron. Both dodecahedra have the same center
and the edges are parallel. I have illustrated this property in a small
animated gif.
I used the "poly" representation of the surface and not "function".
More images can be seen here:
http://cage.ugent.be/~hs
Post a reply to this message
Attachments:
Download 'animbarth04d.gif' (443 KB)
Preview of image 'animbarth04d.gif'
![animbarth04d.gif](/povray.binaries.images/attachment/%3C43437e06%40news.povray.org%3E/animbarth04d.gif?ttop=441697&toff=4900&preview=1)
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hermans wrote:
> Barth's SEXTIC is a surface with 65 double points. It's interesting to
> know that 20 of these double points are the vertices of a regular
> dodecahedron and 30 other double points are the midpoints of the edges
> of another regular dodecahedron.
And the other five?
--
Anton Sherwood, http://www.ogre.nu/
"How'd ya like to climb this high *without* no mountain?" --Porky Pine
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Anton Sherwood schreef:
> hermans wrote:
>
>> Barth's SEXTIC is a surface with 65 double points. It's interesting to
>> know that 20 of these double points are the vertices of a regular
>> dodecahedron and 30 other double points are the midpoints of the edges
>> of another regular dodecahedron.
>
>
> And the other five?
>
That's an interesting question, but I can't give the answer. Perhaps
somebody else can help.
As mentioned in a link on my page concerning this surface, Barth's
sextic is a 6th degree surface that has the maximum number of double
points (65) a 6th degree surface can have.
http://cage.ugent.be/~hs
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Wasn't it hermans who wrote:
>Anton Sherwood schreef:
>> hermans wrote:
>>
>>> Barth's SEXTIC is a surface with 65 double points. It's interesting to
>>> know that 20 of these double points are the vertices of a regular
>>> dodecahedron and 30 other double points are the midpoints of the edges
>>> of another regular dodecahedron.
>>
>>
>> And the other five?
>>
>That's an interesting question, but I can't give the answer. Perhaps
>somebody else can help.
>As mentioned in a link on my page concerning this surface, Barth's
>sextic is a 6th degree surface that has the maximum number of double
>points (65) a 6th degree surface can have.
I spent a while trying to imagine how such a symmetric object could have
an extra 5 points that formed any sort of symmetrical pattern, and
became pretty well convinced that it can't happen.
Then I noticed that 65 - 30 - 20 = 15.
However, I still can't find them, and can't think of any symmetrical
patterns of 15 points that don't have a point at the centre.
--
Mike Williams
Gentleman of Leisure
Post a reply to this message
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