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From: Lars R 
Subject: Superellipsoid parameter gallery
Date: 16 Jan 2012 11:59:52
Message: <4f145788@news.povray.org>
To visualize the effects of the two parameters of the superellipsoid I
rendered this gallery.

I hope you like it. :-)

Lars R.


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Attachments:
Download 'super1024_8.png' (227 KB)

Preview of image 'super1024_8.png'
super1024_8.png


 

From: waggy
Subject: Re: Superellipsoid parameter gallery
Date: 16 Jan 2012 12:55:01
Message: <web.4f1463d15957ea8a9726a3c10@news.povray.org>
"Lars R."wrote:
> To visualize the effects of the two parameters of the superellipsoid I
> rendered this gallery.

Thanks!  That's quite handy.


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From: Stephen
Subject: Re: Superellipsoid parameter gallery
Date: 16 Jan 2012 13:10:14
Message: <4f146806$1@news.povray.org>
On 16/01/2012 4:59 PM, Lars R. wrote:
> To visualize the effects of the two parameters of the superellipsoid I
> rendered this gallery.
>
> I hope you like it. :-)
>
Thanks, I can make use of that. :-D


-- 
Regards
     Stephen


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From: Le Forgeron
Subject: Re: Superellipsoid parameter gallery
Date: 16 Jan 2012 13:45:33
Message: <4f14704d$1@news.povray.org>
Le 16/01/2012 17:59, Lars R. nous fit lire :
> To visualize the effects of the two parameters of the superellipsoid I
> rendered this gallery.
> 
> I hope you like it. :-)

Nice.

Why is it such red ?

2 points:
* there is more past the 2.0 limit (looking at 3, 4 and 5 for instance,
probably not with 1/4 step). Maybe you can use some log/exp scale
instead of a linear one. (1.0 is a must have, 0.5 also, as well as 2.0,
other values might be something along k = 1+log/b (x) ; your choice of
base b.) Central point might remains around 1.0;

* might have some issues of self-shading or computation of intersection
with bounding box or similar for n=0 & e >= 1 (notice the bottom of the
objects on last line)


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From: Lars R 
Subject: Re: Superellipsoid parameter gallery
Date: 16 Jan 2012 18:23:33
Message: <4f14b175@news.povray.org>
>> I hope you like it. :-)

> 
> Nice.
> 
> Why is it such red ?


It looks not so bad on my office LCD. At home it looks more violet and
veries a lot when changing the viewing angle to the screen. Very bad.
You can give me a better rgb value or I try to render with Pov3.7 that
calculates colors differently (physically more correct?), and – even
more important – uses all 4 CPU cores in parallel! :-D

 
> 2 points:
> * there is more past the 2.0 limit (looking at 3, 4 and 5 for instance,
> probably not with 1/4 step). Maybe you can use some log/exp scale
> instead of a linear one. (1.0 is a must have, 0.5 also, as well as 2.0,
> other values might be something along k = 1+log/b (x) ; your choice of
> base b.) Central point might remains around 1.0;

I'll try tomorrow.

> * might have some issues of self-shading or computation of intersection
> with bounding box or similar for n=0 & e >= 1 (notice the bottom of the
> objects on last line)


All superellipsoids are completely inside of a bounding box of
<-1,-1,-1>,<+1,+1,+1>. So I didn't get what you want.

Lars R.


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From: Le Forgeron
Subject: Re: Superellipsoid parameter gallery
Date: 17 Jan 2012 05:54:27
Message: <4f155363@news.povray.org>
Le 17/01/2012 00:23, Lars R. a écrit :
>> * might have some issues of self-shading or computation of intersection
>> with bounding box or similar for n=0 & e >= 1 (notice the bottom of the
>> objects on last line)
> 
> 
> All superellipsoids are completely inside of a bounding box of
> <-1,-1,-1>,<+1,+1,+1>. So I didn't get what you want.

IIRC, a value of 0 is not really recommended in the superellipsoid
documentation: it likes better something like 0.01

(so your range could be 0.01 , , 0.1, , 1, , 10, , 100
and intermediates values might be either (sqrt(10))^k (k from -4 to +4)


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Attachments:
Download 'super_shadow.png' (29 KB)

Preview of image 'super_shadow.png'
super_shadow.png


 

From: Lars R 
Subject: Re: Superellipsoid parameter gallery
Date: 17 Jan 2012 08:14:37
Message: <4f15743d$1@news.povray.org>
> IIRC, a value of 0 is not really recommended in the superellipsoid
> documentation: it likes better something like 0.01

You're right, I noticed that fact already and I add 0.0049 to the 'e'
and 'n' (the largest value so rounding to 2 decimals doesn't show the
difference :-)).

Negative values for e and n are also possible? Oh, I'll try that. :-)

L.


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From: Lars R 
Subject: Extend the parameter range to [0…4]
Date: 17 Jan 2012 10:24:52
Message: <4f1592c4@news.povray.org>
Changelog:

* extend the range from [0…2] to [0…4] with a non-linear scale.
* change the color to blue
* using Povray 3.7 -> artifacts at n≈0 disappear. :-)

But some superellipsoids look strange, i.e. e=2.5,n=0.5. Bug or intention?

Lars R.


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Attachments:
Download 'superelli4_big.png' (2658 KB) Download 'superelli4_2.5_0.5.png' (20 KB)

Preview of image 'superelli4_big.png'
superelli4_big.png

Preview of image 'superelli4_2.5_0.5.png'
superelli4_2.5_0.5.png


 

From: Lars R 
Subject: Extend the parameter range to negtive values
Date: 17 Jan 2012 12:31:14
Message: <4f15b062@news.povray.org>
Negative e gives interesting objects, but negative n gives just dust.

Is there something like a bounded_by option because the objects seem to
extend the  box <-1,-1,1-><+1,+1+1>...

Lars R.


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Attachments:
Download 'superellipsoid_negatives.png' (1409 KB)

Preview of image 'superellipsoid_negatives.png'
superellipsoid_negatives.png


 

From: Reuben Pearse
Subject: Re: Superellipsoid parameter gallery
Date: 17 Jan 2012 17:09:35
Message: <4F15F19C.20507@pearse.co.uk>
This set of reference images would be useful in the POV-Ray manual.


Bye for now

Reuben

=====================================
Download 3D Lego models and other resources from:
http://www.pearse.co.uk/lego
=====================================


On 16/01/2012 16:59, Lars R. wrote:
> To visualize the effects of the two parameters of the superellipsoid I
> rendered this gallery.
>
> I hope you like it. :-)
>
> Lars R.


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